Introduction to Pseudocode for IGCSE Paper 2

foreign [Music] guys this video has been in the making for long so many people have asked me to do this and this involves uh a very second part of computer science that&#39;s very important for paper too so this is everything you need to know about paper two this is all about pseudocode so in today&#39;s video we are going to be having a look at how do I write pseudo code if I have a question on pseudocode how do I write it you know what is pseudocode this is everything you need to know um in regards to this very annoying topic that I used to always have a problem with which was pseudocode okay now for IGCSE it&#39;s a bit easier because what examiners look at is they look at logic they look at the logic of your pseudocode rather than the syntax errors okay and that&#39;s one good part about igcc but you know that&#39;s not what we&#39;re looking for we are looking for the best efficiency of the code we are looking at the best logic okay logic efficiency almost the same thing and with that we are also looking at good syntax okay what that means is we need to have a very efficient code we need to have a very logical code and we also need to have the code to be in in in in relation with the rules of pseudocode like the indentation the case and italics the font and size uh everything related to that okay the different types of arrays and that&#39;s what we&#39;re going to learn uh in today&#39;s video we&#39;re going to learn the different components that make up a pseudocode so this is for beginners this is for people who have been doing pseudocode also before maybe you&#39;re having your exam in a few months this video will help you with your Basics will help you grasp everything that you need to know about pseudocode okay so further Ado let&#39;s begin now in today&#39;s video I will be using the IGCSE pseudocode guide okay because I believe that this guide has everything you need to know even it has irrelevant details that can you know help you uh in one way or another like you know for example you can even see font style and size it will tell you what type of style this IGCSE is using okay so it&#39;s very detailed and I&#39;ll be having um this document down in the description I&#39;ll put the link to this document down in the description if you don&#39;t follow this video uh whereby I will be explaining each part of the guide you can just go down in the description if you want if maybe you&#39;re doing some last minute revision you can read through this this is a very good document for those people who want to improve in your pseudo code so let&#39;s begin and let&#39;s look at the different components for pseudocode now you know before starting with this um topic what is pseudocode you know people always say um pseudocode is english-like statements that represent code okay but what exactly is pseudo pseudocode in other words is simply if you have a long list okay pseudo code is simplifying this list okay into groups maybe okay or into a simpler version of it the reason why in IGCSE we do not learn the code like python Java is because you know the area of programming is Ever Changing okay there is new forms of code every day there&#39;s new forms of ways to write the codes every day there&#39;s different um you know ways to represent data in today&#39;s world therefore igcc they are teaching you the fundamental language for all these codes which is pseudocode I can write pseudocode and can make it to any type of code I want in the future and that&#39;s the reason why we look at pseudocode okay we do not look at a specific programming language like python because if I learn python my knowledge will be limited okay I will not know how to write Java if I know only python okay and you know the reason why we learn pseudocode is you never know what will happen to python 10 years later python will be absolute okay so therefore it&#39;s really important to learn pseudocode rather than the programming language okay so that&#39;s your reason why we need to learn this pseudo code okay some people think that this is useless but this is actually more important than learning your codes okay of course in your free time if you have a specific programming language that you like python Java do that but for IGCSE you need to learn pseudo code you need to learn the fundamentals of coding with the help of pseudocode okay so that&#39;s my uh view on solo code and let&#39;s now go over how to write this sudo okay because I know you have clicked on this video to understand how to write this pseudo code how to get your marks for paper two okay now pseudocode makes up to 60 70 of the paper too there is query tables and Truth tables in the other part of paper too but pseudocode is a very very important fundamental of paper too and you must practice this and must understand this so after this video I&#39;ll be making a video on practice questions on pseudocode so now that after you watch this video you need to apply it to the IGCSE questions okay because a very important thing to do and revision when revising is once when you revise everything you need to apply it okay you cannot just read all your notes and then sit for an exam you have to use those skills to apply it in your examination okay so that will help your examination skills okay let&#39;s stop the Chit Chats and let&#39;s begin with the pseudo code now let&#39;s start off with the first uh and and we have separated this into chapters according to the guide and the first chapter is the basics how is pseudocode uh appeared in the exam how you know do we find these pseudocodes how are the questions tested on this pseudocode is what we look at in the chapter one so in chapter one we&#39;re looking at the font style and size okay you can see this is so so detailed like it&#39;s telling you how pseudocodes will appear and this is very important in code because a computer will always notice the most smallest mistakes that you make if you for example make a mistake of uh putting a capital letter instead of a small C for example it will not run the code and therefore it&#39;s so important that you be careful with even how you write this code okay and therefore we&#39;re starting off with font style and size now in examinations in the paper to pseudocode will appear in this type of font okay in this type of font and this is whenever you see a question with this type of font you know that it&#39;s related to pseudocoder okay now here it&#39;s saying that pseudocode is presented in a mono spaced mono space means it is all together you cannot write c o u like this to write to spell Courier okay you cannot write this this will be given wrong it has to be mono spaced which means fixed width meaning they all have to be with an equals page together what I&#39;ve just written here would be read as c space o space u space r i e r which is wrong it&#39;s not the same meaning as Korea okay so it&#39;s very important to you know keep this in mind these small details in mind and right now you might think you know this is just the most Basics but we&#39;ll get away up to the more advanced stuff like how to write lists how to write arrays and so on and so forth okay so just keep in mind find these small um small types of fundamentals of pseudocode okay because this is really important the next most important thing is indentation it is as important as you use in coding so this indentation here is very important okay because indentation okay indentation helps to show when do we start the code when do we end this code okay and indentation is used for segments okay this is one segment this is a next segment if I&#39;m starting an if statement this if statement is for this um segment if I&#39;m starting a for Loop okay it&#39;s for this segment okay so indentation is really really important so let&#39;s look at the rules for indentation let&#39;s look at uh how to do this indentation because many students struggle with indentation they don&#39;t know when to indentate or if that&#39;s a word but oh yeah when to indent sorry uh so this is very important so let&#39;s have a look at this now according to igcc they&#39;re saying that the lines are in the indented by four spaces to indicate that they are contained within a statement in a previous line so if I&#39;m writing let&#39;s say these size to indentate I will write off the font like this this space here is the indentation okay I know you already know this through English but I&#39;m just giving how I&#39;m giving an example of how indentation looks like next thing where it is not possible to fit a statement on one line any continuation lines are indented by two spaces now this is Barely Used okay but what is trying to say if I have a line here the indentation will be like this this right here is my indentation this space here is called my indentation okay very small small aspects of pseudocode that is very important that you need to know and if you ever forget indentation your code will be wrong so indentation is very very important now right now you don&#39;t know what is indentation how do I do in addition when do I do indentation we will have a look at that later we will have a look at when we in then we indent and when we do not okay so we&#39;ll have a look at that later in the latter part of this video let&#39;s move it the next part of it let&#39;s look at case and italics as I said previously everything in computer science is very very um precise okay where a capital letter can give the entire code wrong and if you do a programming language from before you know that you know most code is case sensitive okay and the computer is very case sensitive so the same thing applies in pseudocode keywords which we&#39;ll learn later is always in uppercase like this if repeat procedure okay we look at the different keywords later as it&#39;s saying here the next thing is identifiers are in mixed case identifiers we&#39;ll have again a look at that like a variable stuff that you will keep using again and again is in mixed case like number of players this is an example for a mixed case this is an example for identifiers sometimes most teachers call this camel case or Pascal case okay that means they have uppercase and they have lowercase that is called camel case like the first letter in number of players is capital then it says number then capital O of capital B players this is case and italics okay this means that there is uppercase and lowercase okay now if you don&#39;t understand what&#39;s happening here when do I indentate when do I use these identifiers when do I use keywords do not worry about this okay the way I&#39;m going to approach this is I&#39;m going to give you each rule one at a time okay and then later it will be like a building block and we will just join everything together so right now if you don&#39;t understand just go with it and just understand that keywords are always in uppercase now if you don&#39;t know what a keyword is don&#39;t worry about that as I said previously we will look at the different keywords and what a keyword does in pseudocode we will look at identifiers and what an identifier does okay so that&#39;s how we do this okay that is how we um do this now this meta variables is not that used in IGCSE uh basically they show this to show that there&#39;s something in here there&#39;s a statement shown here that is just simplified to like the statements but usually there&#39;s something in here until here condition that means in these um brackets there is a condition okay so you don&#39;t really need to understand this that much but this is also an aspect of pseudocode okay so that is that okay I&#39;m hoping you have understood these three font style and size indentation case anthonics let&#39;s look at the last two okay and let&#39;s have a look at lines and numbering okay now there&#39;s a question in computer science where they ask you to locate the error okay in a certain line and therefore lines and numbering is very important in pseudocode because in pseudo code we are always going line by line okay that means the code is executed line by line okay whatever I write in the first one like I say do run then do sleep this means I will first run and then I will sleep if I did this in a reverse way it will first sleep and then it will run so pseudocode is always in order okay it is always in order therefore lines and numbering is very very important so line numbers are consecutive okay unless I have skipped a certain line and unless I have told my code to do one of the following in a order okay but it is always consecutive just like python okay just like that okay so this one not a lot to explain about just shows that pseudocode is always consecutive always in a line always or numbered so if I have one two three line three it will show my code here line two it will show my code here okay so that&#39;s what you need to understand yeah finally we go to the last one and this one is usually you it&#39;s not a must to use but for example I want to be more precise for example I write my code I write something and I want to explain this code within my code we use some feature called comments comments to use comments you do a double slash and then you write whatever you want to explain so if I write a code here write a code here double slash and I write my comment this double slash will not be executed by the program but the double slash means it is a comment okay and a comment is simply refers to the code and usually a comment is explanation of your code like if I run some code the comments will say this code will do this okay for example so that is what we mean by comments okay so to ever write a comment do double slash so I write my code write my code double slash and I dread my and I explain what my code does but again it&#39;s not a must to write comments and you&#39;re not required to write comments in IGCSE but if you want some people do prefer to write comments so that maybe the examiner can understand more it is not a must but you can and if you want you write with two slashes and now in Python it is a hashtag but in pseudocode it&#39;s a slash so if you write a hashtag you will be given wrong so always right with a double slash okay so that is all with the components of pseudocode that is how um you know pseudocode is in simple words written like in all in in words we have alphabets in pseudocode we have these aspects okay we have the lines and numberings the case and italics the indentation the font style and size and the comments okay so these are the four uh is it four or five this is the five fundamental rules of pseudocode that you must obey now as we go later and later you will understand where we apply these five rules like as I said in the case and italics What are keywords what are identifiers we will have a look at that later on the next part that we&#39;re going to be having a look at is variables constants and data types okay so let&#39;s start off with the atomic type names and to understand the atomic type names we can use our own English system now in a sentence we can say maybe the cat likes the milk this is a sentence in the English system and in this sentence we have words a sentence is comprised of words words are comprised of letters so in this case we have the sentence itself we have the words and then we have the letters these would be the atomic data types for our English system and the same way we have it in pseudocode okay and we have five of them okay we have five Atomic data types now sometimes they can ask you just simply in paper to name the data type that is more suitable so this is really important for us to understand the first one is integer and coming from its name just like English integer represents whole number so any time in your code you have a whole number like 21 that is always an integer this is classified as an integer we will later get to know why do we have to classify everything now you know for now let me just quickly introduce to you why we need to categorize all of this for example I am making a program okay and this program is asking the user to input a certain value the computer will only understand if you tell the computer which value it will receive will it receive an integer will it receive a string will it receive a chart and therefore with pseudo code you have to specify which value the computer will get and therefore we categorize our data into these five types okay the first type is integer the value the computer can receive could be an integer like for example the input will be uh user please input our number okay and the value to be inputted would be an integer okay so you need to understand that in programming in pseudo code the computer doesn&#39;t know which value it will receive and therefore you have to specify which value it will get the next one is the real what is the real a real is a number capable of containing a fractional part for example usually reals are in decimals okay another name of real that sometimes uh you can call it is called a float okay but this name is usually for python okay therefore we do not involve it in pseudocode but maybe you must have heard of the name float which is the same thing as a real okay that means any fraction like five over seven would be a real the next one is a Char a Char is simply A Single Character like a b c one even numbers could be a chart okay actually a number is an integer sorry you cannot have a number a chart is simply an alphabet that&#39;s just singular the next one is a string a string is a group of letters together that make up you know a string so a string in other words another name to a string is simply a word in English we would say a string is a word and finally Boolean is when the value can only be true or false there&#39;s only two values for a Boolean okay so I&#39;m hoping you have understood what data types are and data is very very important in computer science okay because everything we learn around revolves around data and how we basically extract data how we understand the data and how we basically manipulate the data through how we want it to be so this is called Atomic type names another name for that is data types so we have five data types that you must remember for this syllabus let&#39;s move on to something called literals now literals are basically they&#39;ve given now examples to what I was talking about above like integers could be 5 negative three those are integers so integers you know it says a whole number but it could be a negative number as well real I said is in decimals or in fractions usually you cannot um show the computer into a fraction form therefore we write it in decimal forms a chart Single Character like XC also at exclamation all of that hashtag those are all single characters a string this is a string group of words that is a string and Boolean only true and false okay so those are just examples to the above data types that you must remember now let&#39;s remember let&#39;s talk about something called identifiers okay when we previously talked about identifiers I said we will come to this but what are identifiers identifiers there are several ways to describe identifiers first of all as you can see it could be a variable it could be a constant it could be a procedure and it could be a function these are the four fundamental aspects of an identifier an identifier could be a variable an identifier could be a constant a procedure and a function you will have a look at all of the four right now in a in a moment they can only contain letters and digits and they must start with a letter and not a digit okay now in programming it&#39;s good practice to use identify names that describe of course the four that I said variable procedure or a function they refer to and single letters may be used where these are conventional such as I and J you later understand what this means this means whenever we write a for example a loop usually we say I or J because those are most of the conventional single letters you know for example in algebra we always use x right the same way in computer science we use I and J but again right now I will tell you how you use them later okay now identifiers we have four identifiers okay we have the variables the constants the procedures and the functions okay so now let&#39;s have a look at those um four and we&#39;re going to start off with the assignments the assignments uh uses something called an arrow okay and this arrow is used to make a variable now what is a variable a variable is an element in the data structure okay that can be assigned to something okay for example if I assign X to 5 every time in the code I refer to this x it will mean it is 5. so I can say later on in the program X plus 2 which will be 5 plus 2 which will give me an output of 7. and what I just did here is what we called a variable a variable assigns something assigns a value to something assigns a string to something and this is our first identifier okay our first identifier is a variable and there are many rules you need to know for a variable like first of all you can never have two words together like for example you cannot say uh name one is five you can never write this two words in a variable can never be done what you have to do is you have to put an underscore for them to be called a variable okay I&#39;m hoping you must have learned this somewhere in some sort of way where the variable must agree with some rules the next thing is you cannot say n and then capital A and then M and then capital E this is wrong you must use the camel case method which we talked about some other uh just uh some five minutes ago which is capital n and then small m e that is how you do the next day you cannot start off with a digit okay like what it said up here they must start with a letter and not a digit this is another rule okay and the centered letters um and other characters including the underscore okay so this is uh something different okay this is talking about um mixed case yeah okay this is something else I am talking about variables okay so these are how you write the variables let&#39;s move on to now an example of this variable so this is an example of variables counter is equals to zero okay counter is equal to zero this is a variable counter is equals to counter plus one this is a variable all these three are examples of variables which are called assignments okay so for now you need to understand how variables are for this um for this syllabus procedures and functions come later on and the as level so right now you do not need to understand that but for now you just need to understand that procedures and functions are part of identifies constants are stuff that remain the same throughout the code like counter is equals to zero will always be counter is equal to zero if you do not change it this means it is a constant a constant coming from its name will never change throughout the program Okay so we&#39;ve discussed quite a lot of stuff in this chapter we talked about data types we talked about the ways we represent the stack type so let me quickly go through the summary of what we just talked about so first of all we talked about the five data types the five data types are used for us to represent data in different forms then we talked about the variable and the constants we use variables in a programming language to simplify our work and in order to basically assign something to another thing okay that&#39;s how variables work and then we have constants will stay the same throughout okay and these are called assignments let&#39;s move on to something called arrays arrays are now a more um a different way to represent data okay arrays are now a more complex way to assign something okay now for example I have a list and I want to assign it to something we use the arrays to list it or we use the arrays to actually do it but let&#39;s start off with what are arrays now arrays are structures of elements okay that are accessible by the indexed okay now we use arrays for a list of stuff we use it for a list of stuff whereby we have a lot of um you know names for example we have a lot of scores for example we use something called an array and if you do programming you know what an array is it has the same idea be behind pseudocode there are different types of arrays now we have one Dynam one dimensional arrays and we have 2D arrays okay we also have 3D arrays but we don&#39;t talk about that let&#39;s start off with the one deal day okay now the 1D array is pretty simple okay now you see this array declaration it is not required in your syllabus you don&#39;t need to unders you don&#39;t need to declare any array you will get that later on on how to declare arrays in the as level for now you just need to know how to make these arrays and to make these arrays it&#39;s pretty simple okay now for example I have an array and if we just ignore this right now this is how you write an array student names array 1 to 30 of string so this means I have a student names I have 30 names and they all are strings now where do we use arrays okay now for example I have this array and I want for example a certain person in that array okay here&#39;s where it is using arrays if I write student names and then the index okay if I write the index okay if I write this it will out to Output me the first person in that array and then I can use that data in my code somewhere now the best way to practice pseudocode is of course by doing questions okay so right now you might not understand what&#39;s happening what are these arrays what are these variables what are these constants the only way to understand them is by using them in real life scenarios or by doing them through questions which I said is going to be the next video so right now let&#39;s just understand Theory and then once when we go to the actual questions you will understand more the next thing assigning an array assigning an array is just saying saved game not 10 crosses this is assigning an array usually we say it&#39;s like this this is how you assign an array okay so this is how we do it we look at we look at the different types of Loops later okay we&#39;ll look at Loop structures later so for that we&#39;re going to leave that right now so let&#39;s now talk about operations because coding of course involves a series of operations okay you must know how to um oh where is it okay so let&#39;s talk about operations now foreign operation and the most simple operation is the input and output operation coming from the name input is to enter an output is to display so values are input with a certain type of keyword okay and here let me introduce now what keywords are later on in the start we said something called keywords must be in case in format so what are these keywords and we&#39;re going to start off with the first keyword and the first keyword is the input and the output keyword the input in the output keywords are simply coming from the name then do something if I input something it will input it okay if I output something it will output it okay and these keywords do the job okay and there are several keywords you need to remember that are in the back of this worksheet so if I quickly go to the back of this worksheet um if I go to the back of the worksheet you can see here these are the symbols and the keywords you need to know so all these are the only keywords you need to know for your syllabus so remember all these keywords remember what they do okay I cannot teach this I can only teach what these keywords do I cannot tell you to cram this remember this this you need to remember okay so these are the most um keywords that are encountered in your syllabus along with the symbols that you need to know for example the symbols that involve the variables the asterisk uh the comments all that you need to understand uh to okay so that also you need to understand so let&#39;s cut back to let&#39;s get back to the input and output and let&#39;s talk more about uh the keywords right now okay so the most simple keywords are of course the input and output as they say from the meaning one inputs one outputs another thing you need to note if you want to Output several items you can use commas which it says here like this you have comma lives comma lives left another thing you can do is you can output variables okay you can output variables you can output arrays you can output the index of the arrays like a certain amount the same way with inputs you can input a variable you can input a lot of variables you can input a lot of values through the help of this another thing you need to note is for this syllabus you can say read and you can say print which means the same thing as input and output but mostly even in the questions you you will be seeing input and output more so I&#39;d advise you to use input and output so these are your first keywords that you need to know let&#39;s now have a look at the arithmetic operations now with the data you can do a lot of operations in computer science and the basic operations would be the addition operation subtraction multiplication and division and these are the symbols for the following okay they&#39;re just like maths except maybe the asterisks but I know even that now people use in maths addition subtraction as tricks and division would be the backslash these are how you do additions for example five plus five would be ten five minus five would be zero five times five would be 25 5 divided by five would be whatever one over zero whatever one in that case Okay so that is how you divide okay now another thing you need to have a look at okay is something called operators like mode and div now for these usually they will explain it uh in the question so we don&#39;t need to actually uh understand this right now so much with more than div so they will explain it in the question what mode does what Dev does so don&#39;t worry about that okay now uh let&#39;s have a look at logic operators okay these are more keywords okay these were keywords there are more keywords so now we&#39;re learning the different keywords the next keyword you need to know is and or and not okay and over and not so these are all Boolean types as it says and in complex Expressions you can use these okay but let&#39;s have a look at the example of where they are used so we come here okay they are not explained here but these are just other keywords that you need to understand that could you could use for example if you want to carry out two operators like do this this and uh sorry spell that wrong do is this is where you use and then you can use or or if this or this do this okay stuff like that that is where you use those logic operators now let&#39;s have a look at selections let&#39;s have a look at statements okay these are very very important and these are the main things you need to understand uh in order to probably write a pseudo code so when having a look about the if statements the general structure of an if statement is as it shows here if there&#39;s a condition and I&#39;ll give an example with this if the weather is equals to Sunny then output do not use umbrellas and if okay that&#39;s a simple way to write a program called in sudokode if a condition so the condition you could say so many stuffs if this is equals to this if this is not equals to this if this is greater than this so like you can say if a is greater than b then then I&#39;ll do a statement then then you say output a output B whatever you want to do and then say end this but if you have maybe several conditions or if your condition can have two outputs for example if a is greater than b then I will do this else if B is greater than a then it will do this so this is the simple structure of an if statement and this is when indentation becomes important as I said in the start indentation is very very important and usually indentation is in igcc is used in loops and there are several Loops you need to understand and this is your first Loop the first Loop is the if Loop and we say the if Loop is called the selection Loop because we select stuff data types throughout the coding okay so this is how you write an if statement in the next video we will use this if statement to make a program so right now understand how an if statement is written if then a condition and I told you these brackets simply mean it shows whether it&#39;s a condition whether it&#39;s a statement I&#39;ve talked about all of this before the capital f means it is a keyword the capital then means it is a keyword and if means it&#39;s a keyword okay so I&#39;m trying I&#39;m trying uh you know now I&#39;m using those previous stuff that I explained in this the indentation is all needed in the loop too okay so that is how you do now in more complicated stuff we say there&#39;s something called nested if statements if I have an if here I will have an if within the if this is called a nested if statement so let&#39;s go through this if statement if challenges score is greater than Champion score then if challenges go is greater than higher score so if this is true okay if this is true it will go to this one if this is true then it will output blah blah blah if it&#39;s not if this is okay look if this is um if this is true it will go and execute this right here but if it is false it will execute this here and then it&#39;ll end if and if all of this is false then it will go do this if the first statement was false okay for example if Challenger score is not greater than Champion score it will do this directly it will output Champion name then again we have an if statement if this blah blah if this is true it will output this otherwise it will do nothing this is called a nested if statement it&#39;s a bit more complicated and it takes some time to understand but over time don&#39;t worry you will get the idea after we do more questions you will understand and you&#39;ll think um way better in when you&#39;ll need the nested if statements and how you can use these next step if statements the next one is the case statements and I really like this because it&#39;s so simple a case statement is when you have several um statements to be executed depending on a value of a variable okay and an example of a case statement is this so this is the structure of a case statement case of the identifier so in this case it would be an identifier is the variable the constants the procedure and the functions but remember in our syllabus we don&#39;t need procedures and functions okay so case of variable value 1 value 2 statement statement indication then okay usually it&#39;s an otherwise okay so this is if there&#39;s otherwise so it&#39;s usually case of otherwise okay so if the first of all of this is false then we will do otherwise for example case of identifier value one statement value two statement otherwise statement any case okay now let&#39;s give an example the best way to understand this is through examples so let&#39;s see first of all input move we talked about what input does input simply will input move okay so right here it&#39;ll say input move case or move move is now a variable w a s t and it&#39;s giving us the position okay so if a move is W then it will do this okay if the move is as it will do this if the move is a we will do this if it is for example P then it will beep so right now we are only doing wasd now you know why this is important for example we are making a game we will only use wasd and this is how you format it in sudo code okay so I&#39;m hoping you understand and usually always these Loops they end and they start so this would be the start of the the thing and this would be the end okay the same way for the if statement there was a start here and there was an end year let&#39;s look at the next Loop the next Loop is the for Loop so this is the third Loop that we have talked about the fourth Loop is a controlled Loop okay for variable or identifier value to Value statements so for example I want to do five things at the same time this Loop will go on five times five that&#39;s why it&#39;s called account control Loop it will do it five times okay and this is what we call account control uh loop okay so an example of this is for example total is equals to zero I want you to read this at your own time I don&#39;t know you know keep wasting time but it&#39;s as simple as that this Loop will go on as many times as you tell it to so if you tell it to do five times it will go over five times it will output something five times for example okay this is called a for loop again when do we use each Loop you will get to know when we start doing questions you will get to know you know you have to always choose the most effective group for example I can do something with an if Loop and I can also do something with a for Loop okay that&#39;s how it works so you have to decide which is the best Loop to use until certain scenario the next type of loop we are talking about is called the post condition Loop and this is called the repeat until Loop the structure of a repeat until loop I want you to click the worksheet Down Below in this description I want you to understand all of the formats of these Loops if you are doing uh last minute revision go over how the structure of each of the loops if you are new to pseudocode also understand the different keywords the different identifiers the different structures and the different conditions onto when you use these Loops okay something I cannot teach I can only explain right or you know like I cannot tell you to cram this but this you have to cram you have to cramp the structures okay so repeat statement until the condition is true so keep repeating something until something is true for example that is what this Loop does so it will keep going on and finally the last Loop okay but let&#39;s have a look an example of repeater repeat output please enter the password and then input password until the password is secret so this Loop will keep going on until the password is Secret okay until the password is secret it will keep going if you output something that is not secret it will keep going keep going it&#39;ll keep saying output another password output another password that&#39;s how it works finally the last Loop that you need to know is called the while a while loop is called the precondition so look look at what we have talked about we have talked about a precondition loop and we&#39;ve talked about a post conditioned Loop here post condition Loop is the repeat and until and a precondition loop is the while Loops this is the structure of a while loop while condition do statement and one so while this is true do the statement so an example here would be while the number is greater than 9 so a number could be the variable okay number could be the variable that I&#39;ve said number okay I&#39;d say for example input number and if I say the number is 10 then this code this Loop will execute but if I input the number as 6 this Loop will not run okay so this is called a post condition Loop okay sorry a precondition loop because you need that number in order for the loop two to start okay so this type of um this type of loop cannot even run okay but the post condition Loop always must run once so that marks the end of the loops and that technically is all you need to know for pseudocode you need to know the keywords you need to know the identifiers you need to know the different types of Loops I believe there was five Loops if I&#39;m not wrong yeah there was five Loops that you need to know you need to know all these keywords right here all these keywords what an if does what an input does all that sorts of stuff okay so you need to understand all of this and they&#39;ve also given the page number for each of them where they have mentioned what it does okay so go through this document it&#39;s a very good document this is actually a teacher&#39;s guide that you should go over and remember again I&#39;ll keep emphasizing that IGCSE they look at the logic rather than the syntax but it&#39;s very important for you for the examiner to understand the logic to have good syntax therefore it&#39;s very important to understand how each Loop Works how everything works how keywords work so on so forth but over time these keywords you don&#39;t even need to um you know just naturally comes the way um the way you write word and know the spelling the same way you&#39;ll just know the keywords when to use and where to use it so that marks the end of pseudocode and as as I promised um in the next video guys we will do some questions on the pseudocodes and just improve our skills with pseudocode because I know it&#39;s a very technical type of skill that takes some time and takes some practice but over time you will get much better at Sudoko so hopefully this video helped you so many people ask me to do a video on pseudocode and finally I have made this video so I&#39;m hoping you enjoyed this video and with that being said thank you guys for watching this video and I shall see you in the next video thank you guys

foreign [Music] guys this video has been in the making for long so many people have asked me to do this and this involves uh a very second part of computer science that&amp;#39;s very important for paper too so this is everything you need to know about paper two this is all about pseudocode so in today&amp;#39;s video we are going to be having a look at how do I write pseudo code if I have a question on pseudocode how do I write it you know what is pseudocode this is everything you need to know um in regards to this very annoying topic that I used to always have a problem with which was pseudocode okay now for IGCSE it&amp;#39;s a bit easier because what examiners look at is they look at logic they look at the logic of your pseudocode rather than the syntax errors okay and that&amp;#39;s one good part about igcc but you know that&amp;#39;s not what we&amp;#39;re looking for we are looking for the best efficiency of the code we are looking at the best logic okay logic efficiency almost the same thing and with that we are also looking at good syntax okay what that means is we need to have a very efficient code we need to have a very logical code and we also need to have the code to be in in in in relation with the rules of pseudocode like the indentation the case and italics the font and size uh everything related to that okay the different types of arrays and that&amp;#39;s what we&amp;#39;re going to learn uh in today&amp;#39;s video we&amp;#39;re going to learn the different components that make up a pseudocode so this is for beginners this is for people who have been doing pseudocode also before maybe you&amp;#39;re having your exam in a few months this video will help you with your Basics will help you grasp everything that you need to know about pseudocode okay so further Ado let&amp;#39;s begin now in today&amp;#39;s video I will be using the IGCSE pseudocode guide okay because I believe that this guide has everything you need to know even it has irrelevant details that can you know help you uh in one way or another like you know for example you can even see font style and size it will tell you what type of style this IGCSE is using okay so it&amp;#39;s very detailed and I&amp;#39;ll be having um this document down in the description I&amp;#39;ll put the link to this document down in the description if you don&amp;#39;t follow this video uh whereby I will be explaining each part of the guide you can just go down in the description if you want if maybe you&amp;#39;re doing some last minute revision you can read through this this is a very good document for those people who want to improve in your pseudo code so let&amp;#39;s begin and let&amp;#39;s look at the different components for pseudocode now you know before starting with this um topic what is pseudocode you know people always say um pseudocode is english-like statements that represent code okay but what exactly is pseudo pseudocode in other words is simply if you have a long list okay pseudo code is simplifying this list okay into groups maybe okay or into a simpler version of it the reason why in IGCSE we do not learn the code like python Java is because you know the area of programming is Ever Changing okay there is new forms of code every day there&amp;#39;s new forms of ways to write the codes every day there&amp;#39;s different um you know ways to represent data in today&amp;#39;s world therefore igcc they are teaching you the fundamental language for all these codes which is pseudocode I can write pseudocode and can make it to any type of code I want in the future and that&amp;#39;s the reason why we look at pseudocode okay we do not look at a specific programming language like python because if I learn python my knowledge will be limited okay I will not know how to write Java if I know only python okay and you know the reason why we learn pseudocode is you never know what will happen to python 10 years later python will be absolute okay so therefore it&amp;#39;s really important to learn pseudocode rather than the programming language okay so that&amp;#39;s your reason why we need to learn this pseudo code okay some people think that this is useless but this is actually more important than learning your codes okay of course in your free time if you have a specific programming language that you like python Java do that but for IGCSE you need to learn pseudo code you need to learn the fundamentals of coding with the help of pseudocode okay so that&amp;#39;s my uh view on solo code and let&amp;#39;s now go over how to write this sudo okay because I know you have clicked on this video to understand how to write this pseudo code how to get your marks for paper two okay now pseudocode makes up to 60 70 of the paper too there is query tables and Truth tables in the other part of paper too but pseudocode is a very very important fundamental of paper too and you must practice this and must understand this so after this video I&amp;#39;ll be making a video on practice questions on pseudocode so now that after you watch this video you need to apply it to the IGCSE questions okay because a very important thing to do and revision when revising is once when you revise everything you need to apply it okay you cannot just read all your notes and then sit for an exam you have to use those skills to apply it in your examination okay so that will help your examination skills okay let&amp;#39;s stop the Chit Chats and let&amp;#39;s begin with the pseudo code now let&amp;#39;s start off with the first uh and and we have separated this into chapters according to the guide and the first chapter is the basics how is pseudocode uh appeared in the exam how you know do we find these pseudocodes how are the questions tested on this pseudocode is what we look at in the chapter one so in chapter one we&amp;#39;re looking at the font style and size okay you can see this is so so detailed like it&amp;#39;s telling you how pseudocodes will appear and this is very important in code because a computer will always notice the most smallest mistakes that you make if you for example make a mistake of uh putting a capital letter instead of a small C for example it will not run the code and therefore it&amp;#39;s so important that you be careful with even how you write this code okay and therefore we&amp;#39;re starting off with font style and size now in examinations in the paper to pseudocode will appear in this type of font okay in this type of font and this is whenever you see a question with this type of font you know that it&amp;#39;s related to pseudocoder okay now here it&amp;#39;s saying that pseudocode is presented in a mono spaced mono space means it is all together you cannot write c o u like this to write to spell Courier okay you cannot write this this will be given wrong it has to be mono spaced which means fixed width meaning they all have to be with an equals page together what I&amp;#39;ve just written here would be read as c space o space u space r i e r which is wrong it&amp;#39;s not the same meaning as Korea okay so it&amp;#39;s very important to you know keep this in mind these small details in mind and right now you might think you know this is just the most Basics but we&amp;#39;ll get away up to the more advanced stuff like how to write lists how to write arrays and so on and so forth okay so just keep in mind find these small um small types of fundamentals of pseudocode okay because this is really important the next most important thing is indentation it is as important as you use in coding so this indentation here is very important okay because indentation okay indentation helps to show when do we start the code when do we end this code okay and indentation is used for segments okay this is one segment this is a next segment if I&amp;#39;m starting an if statement this if statement is for this um segment if I&amp;#39;m starting a for Loop okay it&amp;#39;s for this segment okay so indentation is really really important so let&amp;#39;s look at the rules for indentation let&amp;#39;s look at uh how to do this indentation because many students struggle with indentation they don&amp;#39;t know when to indentate or if that&amp;#39;s a word but oh yeah when to indent sorry uh so this is very important so let&amp;#39;s have a look at this now according to igcc they&amp;#39;re saying that the lines are in the indented by four spaces to indicate that they are contained within a statement in a previous line so if I&amp;#39;m writing let&amp;#39;s say these size to indentate I will write off the font like this this space here is the indentation okay I know you already know this through English but I&amp;#39;m just giving how I&amp;#39;m giving an example of how indentation looks like next thing where it is not possible to fit a statement on one line any continuation lines are indented by two spaces now this is Barely Used okay but what is trying to say if I have a line here the indentation will be like this this right here is my indentation this space here is called my indentation okay very small small aspects of pseudocode that is very important that you need to know and if you ever forget indentation your code will be wrong so indentation is very very important now right now you don&amp;#39;t know what is indentation how do I do in addition when do I do indentation we will have a look at that later we will have a look at when we in then we indent and when we do not okay so we&amp;#39;ll have a look at that later in the latter part of this video let&amp;#39;s move it the next part of it let&amp;#39;s look at case and italics as I said previously everything in computer science is very very um precise okay where a capital letter can give the entire code wrong and if you do a programming language from before you know that you know most code is case sensitive okay and the computer is very case sensitive so the same thing applies in pseudocode keywords which we&amp;#39;ll learn later is always in uppercase like this if repeat procedure okay we look at the different keywords later as it&amp;#39;s saying here the next thing is identifiers are in mixed case identifiers we&amp;#39;ll have again a look at that like a variable stuff that you will keep using again and again is in mixed case like number of players this is an example for a mixed case this is an example for identifiers sometimes most teachers call this camel case or Pascal case okay that means they have uppercase and they have lowercase that is called camel case like the first letter in number of players is capital then it says number then capital O of capital B players this is case and italics okay this means that there is uppercase and lowercase okay now if you don&amp;#39;t understand what&amp;#39;s happening here when do I indentate when do I use these identifiers when do I use keywords do not worry about this okay the way I&amp;#39;m going to approach this is I&amp;#39;m going to give you each rule one at a time okay and then later it will be like a building block and we will just join everything together so right now if you don&amp;#39;t understand just go with it and just understand that keywords are always in uppercase now if you don&amp;#39;t know what a keyword is don&amp;#39;t worry about that as I said previously we will look at the different keywords and what a keyword does in pseudocode we will look at identifiers and what an identifier does okay so that&amp;#39;s how we do this okay that is how we um do this now this meta variables is not that used in IGCSE uh basically they show this to show that there&amp;#39;s something in here there&amp;#39;s a statement shown here that is just simplified to like the statements but usually there&amp;#39;s something in here until here condition that means in these um brackets there is a condition okay so you don&amp;#39;t really need to understand this that much but this is also an aspect of pseudocode okay so that is that okay I&amp;#39;m hoping you have understood these three font style and size indentation case anthonics let&amp;#39;s look at the last two okay and let&amp;#39;s have a look at lines and numbering okay now there&amp;#39;s a question in computer science where they ask you to locate the error okay in a certain line and therefore lines and numbering is very important in pseudocode because in pseudo code we are always going line by line okay that means the code is executed line by line okay whatever I write in the first one like I say do run then do sleep this means I will first run and then I will sleep if I did this in a reverse way it will first sleep and then it will run so pseudocode is always in order okay it is always in order therefore lines and numbering is very very important so line numbers are consecutive okay unless I have skipped a certain line and unless I have told my code to do one of the following in a order okay but it is always consecutive just like python okay just like that okay so this one not a lot to explain about just shows that pseudocode is always consecutive always in a line always or numbered so if I have one two three line three it will show my code here line two it will show my code here okay so that&amp;#39;s what you need to understand yeah finally we go to the last one and this one is usually you it&amp;#39;s not a must to use but for example I want to be more precise for example I write my code I write something and I want to explain this code within my code we use some feature called comments comments to use comments you do a double slash and then you write whatever you want to explain so if I write a code here write a code here double slash and I write my comment this double slash will not be executed by the program but the double slash means it is a comment okay and a comment is simply refers to the code and usually a comment is explanation of your code like if I run some code the comments will say this code will do this okay for example so that is what we mean by comments okay so to ever write a comment do double slash so I write my code write my code double slash and I dread my and I explain what my code does but again it&amp;#39;s not a must to write comments and you&amp;#39;re not required to write comments in IGCSE but if you want some people do prefer to write comments so that maybe the examiner can understand more it is not a must but you can and if you want you write with two slashes and now in Python it is a hashtag but in pseudocode it&amp;#39;s a slash so if you write a hashtag you will be given wrong so always right with a double slash okay so that is all with the components of pseudocode that is how um you know pseudocode is in simple words written like in all in in words we have alphabets in pseudocode we have these aspects okay we have the lines and numberings the case and italics the indentation the font style and size and the comments okay so these are the four uh is it four or five this is the five fundamental rules of pseudocode that you must obey now as we go later and later you will understand where we apply these five rules like as I said in the case and italics What are keywords what are identifiers we will have a look at that later on the next part that we&amp;#39;re going to be having a look at is variables constants and data types okay so let&amp;#39;s start off with the atomic type names and to understand the atomic type names we can use our own English system now in a sentence we can say maybe the cat likes the milk this is a sentence in the English system and in this sentence we have words a sentence is comprised of words words are comprised of letters so in this case we have the sentence itself we have the words and then we have the letters these would be the atomic data types for our English system and the same way we have it in pseudocode okay and we have five of them okay we have five Atomic data types now sometimes they can ask you just simply in paper to name the data type that is more suitable so this is really important for us to understand the first one is integer and coming from its name just like English integer represents whole number so any time in your code you have a whole number like 21 that is always an integer this is classified as an integer we will later get to know why do we have to classify everything now you know for now let me just quickly introduce to you why we need to categorize all of this for example I am making a program okay and this program is asking the user to input a certain value the computer will only understand if you tell the computer which value it will receive will it receive an integer will it receive a string will it receive a chart and therefore with pseudo code you have to specify which value the computer will get and therefore we categorize our data into these five types okay the first type is integer the value the computer can receive could be an integer like for example the input will be uh user please input our number okay and the value to be inputted would be an integer okay so you need to understand that in programming in pseudo code the computer doesn&amp;#39;t know which value it will receive and therefore you have to specify which value it will get the next one is the real what is the real a real is a number capable of containing a fractional part for example usually reals are in decimals okay another name of real that sometimes uh you can call it is called a float okay but this name is usually for python okay therefore we do not involve it in pseudocode but maybe you must have heard of the name float which is the same thing as a real okay that means any fraction like five over seven would be a real the next one is a Char a Char is simply A Single Character like a b c one even numbers could be a chart okay actually a number is an integer sorry you cannot have a number a chart is simply an alphabet that&amp;#39;s just singular the next one is a string a string is a group of letters together that make up you know a string so a string in other words another name to a string is simply a word in English we would say a string is a word and finally Boolean is when the value can only be true or false there&amp;#39;s only two values for a Boolean okay so I&amp;#39;m hoping you have understood what data types are and data is very very important in computer science okay because everything we learn around revolves around data and how we basically extract data how we understand the data and how we basically manipulate the data through how we want it to be so this is called Atomic type names another name for that is data types so we have five data types that you must remember for this syllabus let&amp;#39;s move on to something called literals now literals are basically they&amp;#39;ve given now examples to what I was talking about above like integers could be 5 negative three those are integers so integers you know it says a whole number but it could be a negative number as well real I said is in decimals or in fractions usually you cannot um show the computer into a fraction form therefore we write it in decimal forms a chart Single Character like XC also at exclamation all of that hashtag those are all single characters a string this is a string group of words that is a string and Boolean only true and false okay so those are just examples to the above data types that you must remember now let&amp;#39;s remember let&amp;#39;s talk about something called identifiers okay when we previously talked about identifiers I said we will come to this but what are identifiers identifiers there are several ways to describe identifiers first of all as you can see it could be a variable it could be a constant it could be a procedure and it could be a function these are the four fundamental aspects of an identifier an identifier could be a variable an identifier could be a constant a procedure and a function you will have a look at all of the four right now in a in a moment they can only contain letters and digits and they must start with a letter and not a digit okay now in programming it&amp;#39;s good practice to use identify names that describe of course the four that I said variable procedure or a function they refer to and single letters may be used where these are conventional such as I and J you later understand what this means this means whenever we write a for example a loop usually we say I or J because those are most of the conventional single letters you know for example in algebra we always use x right the same way in computer science we use I and J but again right now I will tell you how you use them later okay now identifiers we have four identifiers okay we have the variables the constants the procedures and the functions okay so now let&amp;#39;s have a look at those um four and we&amp;#39;re going to start off with the assignments the assignments uh uses something called an arrow okay and this arrow is used to make a variable now what is a variable a variable is an element in the data structure okay that can be assigned to something okay for example if I assign X to 5 every time in the code I refer to this x it will mean it is 5. so I can say later on in the program X plus 2 which will be 5 plus 2 which will give me an output of 7. and what I just did here is what we called a variable a variable assigns something assigns a value to something assigns a string to something and this is our first identifier okay our first identifier is a variable and there are many rules you need to know for a variable like first of all you can never have two words together like for example you cannot say uh name one is five you can never write this two words in a variable can never be done what you have to do is you have to put an underscore for them to be called a variable okay I&amp;#39;m hoping you must have learned this somewhere in some sort of way where the variable must agree with some rules the next thing is you cannot say n and then capital A and then M and then capital E this is wrong you must use the camel case method which we talked about some other uh just uh some five minutes ago which is capital n and then small m e that is how you do the next day you cannot start off with a digit okay like what it said up here they must start with a letter and not a digit this is another rule okay and the centered letters um and other characters including the underscore okay so this is uh something different okay this is talking about um mixed case yeah okay this is something else I am talking about variables okay so these are how you write the variables let&amp;#39;s move on to now an example of this variable so this is an example of variables counter is equals to zero okay counter is equal to zero this is a variable counter is equals to counter plus one this is a variable all these three are examples of variables which are called assignments okay so for now you need to understand how variables are for this um for this syllabus procedures and functions come later on and the as level so right now you do not need to understand that but for now you just need to understand that procedures and functions are part of identifies constants are stuff that remain the same throughout the code like counter is equals to zero will always be counter is equal to zero if you do not change it this means it is a constant a constant coming from its name will never change throughout the program Okay so we&amp;#39;ve discussed quite a lot of stuff in this chapter we talked about data types we talked about the ways we represent the stack type so let me quickly go through the summary of what we just talked about so first of all we talked about the five data types the five data types are used for us to represent data in different forms then we talked about the variable and the constants we use variables in a programming language to simplify our work and in order to basically assign something to another thing okay that&amp;#39;s how variables work and then we have constants will stay the same throughout okay and these are called assignments let&amp;#39;s move on to something called arrays arrays are now a more um a different way to represent data okay arrays are now a more complex way to assign something okay now for example I have a list and I want to assign it to something we use the arrays to list it or we use the arrays to actually do it but let&amp;#39;s start off with what are arrays now arrays are structures of elements okay that are accessible by the indexed okay now we use arrays for a list of stuff we use it for a list of stuff whereby we have a lot of um you know names for example we have a lot of scores for example we use something called an array and if you do programming you know what an array is it has the same idea be behind pseudocode there are different types of arrays now we have one Dynam one dimensional arrays and we have 2D arrays okay we also have 3D arrays but we don&amp;#39;t talk about that let&amp;#39;s start off with the one deal day okay now the 1D array is pretty simple okay now you see this array declaration it is not required in your syllabus you don&amp;#39;t need to unders you don&amp;#39;t need to declare any array you will get that later on on how to declare arrays in the as level for now you just need to know how to make these arrays and to make these arrays it&amp;#39;s pretty simple okay now for example I have an array and if we just ignore this right now this is how you write an array student names array 1 to 30 of string so this means I have a student names I have 30 names and they all are strings now where do we use arrays okay now for example I have this array and I want for example a certain person in that array okay here&amp;#39;s where it is using arrays if I write student names and then the index okay if I write the index okay if I write this it will out to Output me the first person in that array and then I can use that data in my code somewhere now the best way to practice pseudocode is of course by doing questions okay so right now you might not understand what&amp;#39;s happening what are these arrays what are these variables what are these constants the only way to understand them is by using them in real life scenarios or by doing them through questions which I said is going to be the next video so right now let&amp;#39;s just understand Theory and then once when we go to the actual questions you will understand more the next thing assigning an array assigning an array is just saying saved game not 10 crosses this is assigning an array usually we say it&amp;#39;s like this this is how you assign an array okay so this is how we do it we look at we look at the different types of Loops later okay we&amp;#39;ll look at Loop structures later so for that we&amp;#39;re going to leave that right now so let&amp;#39;s now talk about operations because coding of course involves a series of operations okay you must know how to um oh where is it okay so let&amp;#39;s talk about operations now foreign operation and the most simple operation is the input and output operation coming from the name input is to enter an output is to display so values are input with a certain type of keyword okay and here let me introduce now what keywords are later on in the start we said something called keywords must be in case in format so what are these keywords and we&amp;#39;re going to start off with the first keyword and the first keyword is the input and the output keyword the input in the output keywords are simply coming from the name then do something if I input something it will input it okay if I output something it will output it okay and these keywords do the job okay and there are several keywords you need to remember that are in the back of this worksheet so if I quickly go to the back of this worksheet um if I go to the back of the worksheet you can see here these are the symbols and the keywords you need to know so all these are the only keywords you need to know for your syllabus so remember all these keywords remember what they do okay I cannot teach this I can only teach what these keywords do I cannot tell you to cram this remember this this you need to remember okay so these are the most um keywords that are encountered in your syllabus along with the symbols that you need to know for example the symbols that involve the variables the asterisk uh the comments all that you need to understand uh to okay so that also you need to understand so let&amp;#39;s cut back to let&amp;#39;s get back to the input and output and let&amp;#39;s talk more about uh the keywords right now okay so the most simple keywords are of course the input and output as they say from the meaning one inputs one outputs another thing you need to note if you want to Output several items you can use commas which it says here like this you have comma lives comma lives left another thing you can do is you can output variables okay you can output variables you can output arrays you can output the index of the arrays like a certain amount the same way with inputs you can input a variable you can input a lot of variables you can input a lot of values through the help of this another thing you need to note is for this syllabus you can say read and you can say print which means the same thing as input and output but mostly even in the questions you you will be seeing input and output more so I&amp;#39;d advise you to use input and output so these are your first keywords that you need to know let&amp;#39;s now have a look at the arithmetic operations now with the data you can do a lot of operations in computer science and the basic operations would be the addition operation subtraction multiplication and division and these are the symbols for the following okay they&amp;#39;re just like maths except maybe the asterisks but I know even that now people use in maths addition subtraction as tricks and division would be the backslash these are how you do additions for example five plus five would be ten five minus five would be zero five times five would be 25 5 divided by five would be whatever one over zero whatever one in that case Okay so that is how you divide okay now another thing you need to have a look at okay is something called operators like mode and div now for these usually they will explain it uh in the question so we don&amp;#39;t need to actually uh understand this right now so much with more than div so they will explain it in the question what mode does what Dev does so don&amp;#39;t worry about that okay now uh let&amp;#39;s have a look at logic operators okay these are more keywords okay these were keywords there are more keywords so now we&amp;#39;re learning the different keywords the next keyword you need to know is and or and not okay and over and not so these are all Boolean types as it says and in complex Expressions you can use these okay but let&amp;#39;s have a look at the example of where they are used so we come here okay they are not explained here but these are just other keywords that you need to understand that could you could use for example if you want to carry out two operators like do this this and uh sorry spell that wrong do is this is where you use and then you can use or or if this or this do this okay stuff like that that is where you use those logic operators now let&amp;#39;s have a look at selections let&amp;#39;s have a look at statements okay these are very very important and these are the main things you need to understand uh in order to probably write a pseudo code so when having a look about the if statements the general structure of an if statement is as it shows here if there&amp;#39;s a condition and I&amp;#39;ll give an example with this if the weather is equals to Sunny then output do not use umbrellas and if okay that&amp;#39;s a simple way to write a program called in sudokode if a condition so the condition you could say so many stuffs if this is equals to this if this is not equals to this if this is greater than this so like you can say if a is greater than b then then I&amp;#39;ll do a statement then then you say output a output B whatever you want to do and then say end this but if you have maybe several conditions or if your condition can have two outputs for example if a is greater than b then I will do this else if B is greater than a then it will do this so this is the simple structure of an if statement and this is when indentation becomes important as I said in the start indentation is very very important and usually indentation is in igcc is used in loops and there are several Loops you need to understand and this is your first Loop the first Loop is the if Loop and we say the if Loop is called the selection Loop because we select stuff data types throughout the coding okay so this is how you write an if statement in the next video we will use this if statement to make a program so right now understand how an if statement is written if then a condition and I told you these brackets simply mean it shows whether it&amp;#39;s a condition whether it&amp;#39;s a statement I&amp;#39;ve talked about all of this before the capital f means it is a keyword the capital then means it is a keyword and if means it&amp;#39;s a keyword okay so I&amp;#39;m trying I&amp;#39;m trying uh you know now I&amp;#39;m using those previous stuff that I explained in this the indentation is all needed in the loop too okay so that is how you do now in more complicated stuff we say there&amp;#39;s something called nested if statements if I have an if here I will have an if within the if this is called a nested if statement so let&amp;#39;s go through this if statement if challenges score is greater than Champion score then if challenges go is greater than higher score so if this is true okay if this is true it will go to this one if this is true then it will output blah blah blah if it&amp;#39;s not if this is okay look if this is um if this is true it will go and execute this right here but if it is false it will execute this here and then it&amp;#39;ll end if and if all of this is false then it will go do this if the first statement was false okay for example if Challenger score is not greater than Champion score it will do this directly it will output Champion name then again we have an if statement if this blah blah if this is true it will output this otherwise it will do nothing this is called a nested if statement it&amp;#39;s a bit more complicated and it takes some time to understand but over time don&amp;#39;t worry you will get the idea after we do more questions you will understand and you&amp;#39;ll think um way better in when you&amp;#39;ll need the nested if statements and how you can use these next step if statements the next one is the case statements and I really like this because it&amp;#39;s so simple a case statement is when you have several um statements to be executed depending on a value of a variable okay and an example of a case statement is this so this is the structure of a case statement case of the identifier so in this case it would be an identifier is the variable the constants the procedure and the functions but remember in our syllabus we don&amp;#39;t need procedures and functions okay so case of variable value 1 value 2 statement statement indication then okay usually it&amp;#39;s an otherwise okay so this is if there&amp;#39;s otherwise so it&amp;#39;s usually case of otherwise okay so if the first of all of this is false then we will do otherwise for example case of identifier value one statement value two statement otherwise statement any case okay now let&amp;#39;s give an example the best way to understand this is through examples so let&amp;#39;s see first of all input move we talked about what input does input simply will input move okay so right here it&amp;#39;ll say input move case or move move is now a variable w a s t and it&amp;#39;s giving us the position okay so if a move is W then it will do this okay if the move is as it will do this if the move is a we will do this if it is for example P then it will beep so right now we are only doing wasd now you know why this is important for example we are making a game we will only use wasd and this is how you format it in sudo code okay so I&amp;#39;m hoping you understand and usually always these Loops they end and they start so this would be the start of the the thing and this would be the end okay the same way for the if statement there was a start here and there was an end year let&amp;#39;s look at the next Loop the next Loop is the for Loop so this is the third Loop that we have talked about the fourth Loop is a controlled Loop okay for variable or identifier value to Value statements so for example I want to do five things at the same time this Loop will go on five times five that&amp;#39;s why it&amp;#39;s called account control Loop it will do it five times okay and this is what we call account control uh loop okay so an example of this is for example total is equals to zero I want you to read this at your own time I don&amp;#39;t know you know keep wasting time but it&amp;#39;s as simple as that this Loop will go on as many times as you tell it to so if you tell it to do five times it will go over five times it will output something five times for example okay this is called a for loop again when do we use each Loop you will get to know when we start doing questions you will get to know you know you have to always choose the most effective group for example I can do something with an if Loop and I can also do something with a for Loop okay that&amp;#39;s how it works so you have to decide which is the best Loop to use until certain scenario the next type of loop we are talking about is called the post condition Loop and this is called the repeat until Loop the structure of a repeat until loop I want you to click the worksheet Down Below in this description I want you to understand all of the formats of these Loops if you are doing uh last minute revision go over how the structure of each of the loops if you are new to pseudocode also understand the different keywords the different identifiers the different structures and the different conditions onto when you use these Loops okay something I cannot teach I can only explain right or you know like I cannot tell you to cram this but this you have to cram you have to cramp the structures okay so repeat statement until the condition is true so keep repeating something until something is true for example that is what this Loop does so it will keep going on and finally the last Loop okay but let&amp;#39;s have a look an example of repeater repeat output please enter the password and then input password until the password is secret so this Loop will keep going on until the password is Secret okay until the password is secret it will keep going if you output something that is not secret it will keep going keep going it&amp;#39;ll keep saying output another password output another password that&amp;#39;s how it works finally the last Loop that you need to know is called the while a while loop is called the precondition so look look at what we have talked about we have talked about a precondition loop and we&amp;#39;ve talked about a post conditioned Loop here post condition Loop is the repeat and until and a precondition loop is the while Loops this is the structure of a while loop while condition do statement and one so while this is true do the statement so an example here would be while the number is greater than 9 so a number could be the variable okay number could be the variable that I&amp;#39;ve said number okay I&amp;#39;d say for example input number and if I say the number is 10 then this code this Loop will execute but if I input the number as 6 this Loop will not run okay so this is called a post condition Loop okay sorry a precondition loop because you need that number in order for the loop two to start okay so this type of um this type of loop cannot even run okay but the post condition Loop always must run once so that marks the end of the loops and that technically is all you need to know for pseudocode you need to know the keywords you need to know the identifiers you need to know the different types of Loops I believe there was five Loops if I&amp;#39;m not wrong yeah there was five Loops that you need to know you need to know all these keywords right here all these keywords what an if does what an input does all that sorts of stuff okay so you need to understand all of this and they&amp;#39;ve also given the page number for each of them where they have mentioned what it does okay so go through this document it&amp;#39;s a very good document this is actually a teacher&amp;#39;s guide that you should go over and remember again I&amp;#39;ll keep emphasizing that IGCSE they look at the logic rather than the syntax but it&amp;#39;s very important for you for the examiner to understand the logic to have good syntax therefore it&amp;#39;s very important to understand how each Loop Works how everything works how keywords work so on so forth but over time these keywords you don&amp;#39;t even need to um you know just naturally comes the way um the way you write word and know the spelling the same way you&amp;#39;ll just know the keywords when to use and where to use it so that marks the end of pseudocode and as as I promised um in the next video guys we will do some questions on the pseudocodes and just improve our skills with pseudocode because I know it&amp;#39;s a very technical type of skill that takes some time and takes some practice but over time you will get much better at Sudoko so hopefully this video helped you so many people ask me to do a video on pseudocode and finally I have made this video so I&amp;#39;m hoping you enjoyed this video and with that being said thank you guys for watching this video and I shall see you in the next video thank you guys

Transcript for:Introduction to Pseudocode for IGCSE Paper 2

Transcript for:
Introduction to Pseudocode for IGCSE Paper 2