Introduction to Programming Lecture Notes

Overview

• Lecture by Steven and Shawn
• Duration: 90 minutes
• 21 segments covering programming basics applicable to all languages
• Topics include:
  • What is programming?
  • Common features in computer science (loops, arrays)
  • Code reading and writing
  • Debugging and planning strategies

What is Programming?

• Definition: Preparing an instructional program for a device (simplified).
• Purpose: Get a computer to complete specific tasks without mistakes.
• Analogy: Giving very specific instructions to a less intelligent friend (like building a Lego set).
• Understanding Machine Code: Computers only understand binary (machine code).

Programming Languages

• Role: Serve as a middleman to translate human instructions into machine code.
• Types:
  • High-level languages (e.g., Python, Java)
  • Low-level languages (e.g., assembly, C)
• Choosing a Language: Preference based on use case and user comfort.

Writing Code

• Use of Integrated Development Environment (IDE).
• IDEs provide:
  • Graphic interface for writing, running, debugging code
  • Tools like error checking and auto-filling
• Syntax: Rules of a programming language that must be strictly followed; similar to grammar in natural languages.

Print Statement

• Used to output text to the console.
• Example in Python: print("Hello World")
• Important for debugging and viewing program output.

Basic Arithmetic and Strings

• Computers can perform basic math: addition, subtraction, multiplication, division.
• Modulus Operator: Returns the remainder of a division.
• Strings: Text data, manipulated using concatenation.
  • Example: print("Game over! Score: " + str(score))

Variables

• Definition: Storage units for information that can be referenced and manipulated.
• Types of Variables:
  • Primitive types: integers, booleans, floats, doubles, strings, characters.
• Usage: Storing and tracking user inputs or dynamic data.

Conditional Statements

• If Statement: Executes code block based on a condition.
• Else and Else If: Used for additional conditions.
• Example: if (age == 10) { ... } else if (age == 12) { ... }

Arrays

• Definition: Collection of elements stored together.
• Indexing: Accessing elements via their index, starting at zero.
• Two-dimensional arrays: Arrays containing other arrays.

Loops

1. For Loop: Executes a set number of times based on a condition.
   • Syntax: for (int i = 0; i < 10; i++) { ... }
2. While Loop: Continues as long as a condition is true.
   • Example: while (x < 5) { ... }
3. Do-While Loop: Executes at least once; checks condition after.

Error Handling

• Types of Errors:
  1. Syntax Errors: Issues with code structure.
  2. Runtime Errors: Errors during execution (e.g., infinite loops).
  3. Logic Errors: Code runs, but does not yield expected results.
• Debugging Techniques:
  • Read errors from IDE.
  • Use print statements and breakpoints to track down issues.

Functions

• Definition: Segments of code that perform specific tasks, can be reused.
• Types:
  1. Functions that take arguments and return values.
  2. Functions that take arguments but do not return values.
  3. Functions that do not take arguments but return values.
  4. Functions that do not take arguments and do not return values.
• Benefits: Reduces code duplication, simplifies updates.

Importing Functions

• Use of libraries: collections of functions available for use.
• Import syntax varies by language (e.g., Java, Python).

Pseudocode

• Purpose: Planning out code without worrying about syntax.
• Techniques:
  1. Flowcharts.
  2. Step-by-step descriptions of the program.
  3. Listing features needed for the program.

Next Steps in Learning Programming

• Research the programming language of interest.
• Learn through online resources (YouTube, coding challenge sites).
• Take programming classes in school.
• Build projects and contribute to open-source.

Conclusion

• Programming involves understanding concepts, planning, and refining code.
• Explore different languages and tools to find what suits you best.