Introduction to Programming

Basics 3 examples

Programming is the process of creating instructions for computers to execute. In this, you'll learn about programming languages, how to write your first program, and the fundamental concepts that form the foundation of all programming.

What is Programming?

Programming is solving problems by writing step-by-step instructions that a computer can understand and execute. These instructions, called code, tell the computer exactly what to do to accomplish a specific task.

Key Programming Concepts:

Algorithm: A sequence of steps to solve a problem
Syntax: The rules and structure of a programming language
Logic: The reasoning behind solving problems
Debugging: Finding and fixing errors in code

Your First Program

Let's start with the base program in C++:


#include 
using namespace std;

int main() {
    ...
    Code
    ...
    ...
    // This is a comment (not executed by the program, it starts with // or /* and ends with */ in case of multi-line comments)
    return 0;
}

Understanding the Code:

#include <iostream> - Includes input/output functionality
using namespace std; - īAllows us to use standard library functions
int main() - The main function where program execution begins
code - This is where you write your program logic. The functions (like code snippet outsite main() is called from here either indirectly or directly to be executed)
return 0; - Indicates successful program execution

Input and Output

Most programs need to interact with users by taking input and producing output:


#include 
using namespace std;

int main() {
    string name;
    int age;
    cin >> name;
    cout << "Hello " << name << endl;

    string s;
    getline(cin, s);

    return 0;
}

Understanding the Code:

cin - function to take input
cout - function to output data
getline(cin, s) - Reads an entire line of input including spaces

Working with Numbers

Programming often involves mathematical calculations:


#include 
using namespace std;

int main() {
    int num1, num2;
    
    cout << "Enter two numbers: ";
    cin >> num1 >> num2;
    
    cout << "Sum: " << num1 + num2 << endl;
    cout << "Difference: " << num1 - num2 << endl;
    cout << "Product: " << num1 * num2 << endl;
    cout << "Division: " << (double)num1 / num2 << endl;
    
    return 0;
}

Common Beginner Mistakes:

Forgetting semicolons at the end of statements
Mismatching parentheses or brackets
Case sensitivity errors (C++ is case-sensitive)
Integer division truncating decimal results

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