Lecture: C++ Programming Basics

Introduction to C++

• C++ is a fast and efficient language.
• Used in advanced graphics applications (e.g., Adobe software, video editing).
• Commonly used for embedded systems and video game development.
• Middle-level language: closer to hardware than high-level languages (e.g., Python, Java), but still resembles human language.
• Steeper learning curve than higher-level languages, but it's worthwhile.

Getting Started with C++

• Tools Needed:
  • Text Editor: Examples include VS Code, Code Blocks, and Notepad.
    • VS Code and Code Blocks are IDEs with integrated developer tools.
  • Compiler: Converts source code to machine instructions.
    • Windows/Linux: GCC
    • Mac: Clang

Setting Up VS Code

1. Download VS Code from code.visualstudio.com.
2. Install and set it up with default settings.
3. Recommended extensions for C++ development:
   • C/C++ extension
   • Code Runner extension
4. Create a new folder for C++ projects.
5. Create a new file (e.g., hello_world.cpp) in VS Code.

Installing a Compiler

• Linux:
  • Check if GCC is installed: gcc -v
  • Install GNU Compiler Tools: sudo apt-get install build-essential
• Mac:
  • Install XCode Command Line Tools: xcode-select --install
• Windows: (More Steps)
  • Download MinGW-w64 and follow installation instructions.

Writing and Running a Basic C++ Program

1. Include necessary headers and set up the main function:

   #include <iostream>
   
   int main() {
     std::cout << "Hello, world!" << std::endl;
     return 0;
   }
   

2. Run the program using the Code Runner extension.

Working with Output in C++

• Using iostream for basic input and output operations.
• std::cout for output to the console.
• Use \n or std::endl for new lines.
• Using comments for notes:
  • Single-line comments with //
  • Multi-line comments with /* */

Variables and Data Types

• Declaration and assignment:
  • Syntax: datatype variableName = value;
  • Example: int x = 5;
• Common data types:
  • int: integers
  • double: floating-point numbers
  • char: single characters
  • bool: boolean values (true/false)
  • string: sequences of text (requires #include <string>)

Basic C++ Syntax and Control Structures

• If Statements: Used for decision-making
• Switch Statements: Alternative to many else if statements
• Loops:
  • For loops: Execute a block of code a specific number of times
  • While loops: Repeat code as long as a condition is true
  • Do-While loops: Similar to while loops, but the code block is executed at least once

Functions in C++

• Definition:

  returnType functionName(parameters) {
    // code
  }
  

• Example:

  void printHello() {
    std::cout << "Hello!" << std::endl;
  }
  

• Function Prototypes: Declare functions before the main function.
• Parameter Passing:
  • Pass by Value: Copies the argument's value (default).
  • Pass by Reference: Passes the argument's address (&).
  • Const Parameters: Use const to make parameters read-only.

C++ Arrays

• Declaration: datatype arrayName[arraySize];
• Initialization:

  int numbers[5] = {1, 2, 3, 4, 5};
  

• Accessing Elements: Use index notation arrayName[index] starting from 0.
• Multi-dimensional Arrays: Arrays within arrays.
  • Example: int matrix[3][3];

Pointers

• Definition: Variables that store memory addresses.
• Syntax: datatype* pointerName;
• Example:

  int x = 5;
  int* p = &x; // p points to x
  

• Dereferencing: Access the value at the pointer's address using *.

Dynamic Memory Allocation

• Using new to allocate memory in the heap:

  int* p = new int;
  *p = 10;
  

• Deallocating memory with delete:

  delete p;
  

• Example with arrays:

  int* arr = new int[10];
  delete[] arr;
  

C++ Classes and Object-Oriented Programming

• Classes: Blueprints for creating objects.
• Attributes and Methods: Characteristics and actions of the class.
• Syntax:

  class ClassName {
    public:
      datatype attribute;
      returnType methodName(parameters);
  };
  

• Example:

  class Dog {
    public:
      int age;
      void bark() {
        std::cout << "Woof!" << std::endl;
      }
  };
  

• Constructors: Special methods called when an object is instantiated.
• Inheritance: A class can inherit attributes and methods from another class.
• Polymorphism: Methods that behave differently based on the object.

Example Programs

• Simple Calculator
• Tic-Tac-Toe Game
• Number Guessing Game

Summary

• C++ is a versatile and powerful language useful for a variety of applications.
• Mastering the basics such as variables, control structures, arrays, pointers, and object-oriented programming is crucial.
• Practice through projects and exercises to solidify understanding.