💻 C Programming Basics

Author: Megh Badonia
Repository Purpose: Learn the fundamentals of the C programming language with real code examples.

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📌 Introduction to C

C is a powerful general-purpose programming language developed in the early 1970s. It is fast, efficient, and widely used for system/software development, embedded systems, and operating systems like UNIX.

C is a compiled language, meaning your code must be translated into machine code using a compiler before it can be executed.

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🔤 Basic Structure of a C Program

#include <stdio.h>   // Preprocessor directive

int main() {
    printf("Hello, World!\n");  // Output to console
    return 0;                   // Exit status
}

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📦 Data Types in C

Type	Size (Bytes)	Description
int	2 or 4	Integer numbers
float	4	Single-precision float
double	8	Double-precision float
char	1	Single character
void	0	No value (used in functions)

int age = 25;
float pi = 3.14;
char grade = 'A';

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🔧 Variables and Constants

Variables must be declared with a type before use.

int number = 10;
const float GRAVITY = 9.81;  // Constant value

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📐 Operators in C

int a = 5, b = 2;

int sum = a + b;       // Add
int diff = a - b;      // Subtraction
int prod = a * b;      // Multiplication
int div = a / b;       // Integer Division
int mod = a % b;       // Modulus

a += 1;  // Increment
b--;     // Decrement

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🧠 if, else if, else

int num = 15;

if (num > 0) {
    printf("Positive number\n");
} else if (num < 0) {
    printf("Negative number\n");
} else {
    printf("Zero\n");
}

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🔁 Loops in C

1. for loop

for (int i = 1; i <= 5; i++) {
    printf("%d ", i);
}

2. while loop

int i = 1;
while (i <= 5) {
    printf("%d ", i);
    i++;
}

3. do-while loop

int i = 1;
do {
    printf("%d ", i);
    i++;
} while (i <= 5);

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🔣 Switch Statement

int day = 3;

switch (day) {
    case 1: printf("Monday"); break;
    case 2: printf("Tuesday"); break;
    case 3: printf("Wednesday"); break;
    default: printf("Invalid day");
}

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📞 Functions in C

int add(int a, int b) {
    return a + b;
}

int main() {
    int result = add(3, 4);
    printf("Sum: %d", result);
    return 0;
}

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🗂️ Arrays in C

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

for (int i = 0; i < 5; i++) {
    printf("%d ", numbers[i]);
}

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💡 Tips for Beginners

• Always end statements with a semicolon ;
• Use comments to document your code (// single-line, /* multi-line */)
• Indent your code properly for readability
• Compile using gcc filename.c -o output and run with ./output

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👤 Author

Created by Megh Badonia

Feel free to explore, fork, or clone this repository to practice and enhance your C programming skills.

Happy coding! 🚀