Learn C with Real Code Examples

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    int numbers[] = {1, 2, 3, 4, 5};

    int sum = 0;

    for (int i = 0; i < 5; i++) {
        sum += numbers[i];
    }

    printf("Sum: %d\n", sum);
    return 0;

}

A basic C program demonstrating array manipulation, loops, and printf. Calculates sum of numbers in an array.

#include <stdio.h>

int main() {
    int n = 10, sum = 0;
    for (int i = 1; i <= n; i++) {
        sum += i;
    }
    printf("Sum: %d\n", sum);
    return 0;
}

Calculates the sum of first N natural numbers using a for loop and demonstrates basic arithmetic operations.

#include <stdio.h>

int main() {
    int n = 5, fact = 1;

    for (int i = 1; i <= n; i++) {
        fact *= i;

    }

    printf("Factorial: %d\n", fact);

    return 0;

}

Calculates factorial of a number using iterative multiplication. Demonstrates loops and basic math operations.

#include <stdio.h>

int main() {
    int n = 7;

    if (n % 2 == 0)

        printf("%d is Even\n", n);

    else

        printf("%d is Odd\n", n);

    return 0;

}

Uses modulo operator to determine if a number is even or odd. Basic conditional logic demonstration.

#include <stdio.h>

int main() {
    int n = 1234, rev = 0;

    while (n != 0) {
        rev = rev * 10 + n % 10;

        n /= 10;

    }

    printf("Reversed: %d\n", rev);

    return 0;

}

Reverses a number using modulo and division operations. Shows digit manipulation and while loop usage.

#include <stdio.h>

int main() {
    int a = 10, b = 20, c = 15;

    if (a >= b && a >= c)

        printf("Largest: %d\n", a);

    else if (b >= a && b >= c)

        printf("Largest: %d\n", b);

    else

        printf("Largest: %d\n", c);

    return 0;

}

Finds the largest number among three using nested if-else statements. Demonstrates comparison operations.

#include <stdio.h>

int main() {
    int a = 5, b = 10, temp;

    temp = a;

    a = b;

    b = temp;

    printf("a = %d, b = %d\n", a, b);

    return 0;

}

Demonstrates swapping two numbers using a temporary variable. Basic variable manipulation example.

#include <stdio.h>

int main() {
    int n = 10, a = 0, b = 1, c;

    printf("%d %d ", a, b);

    for (int i = 2; i < n; i++) {
        c = a + b;

        printf("%d ", c);

        a = b;

        b = c;

    }

    return 0;

}

Generates Fibonacci sequence using iteration. Shows sequence generation and variable updates.

#include <stdio.h>

int main() {
    int n = 121, orig = n, rev = 0;

    while (n != 0) {
        rev = rev * 10 + n % 10;

        n /= 10;

    }

    if (orig == rev)

        printf("Palindrome\n");

    else

        printf("Not Palindrome\n");

    return 0;

}

Checks if a number reads the same forwards and backwards. Uses digit extraction and reversal.

#include <stdio.h>

int main() {
    int n = 29, isPrime = 1;

    for (int i = 2; i <= n / 2; i++) {
        if (n % i == 0) {
        isPrime = 0;

        break;

        }

    }

    if (isPrime)

        printf("%d is Prime\n", n);

    else

        printf("%d is Not Prime\n", n);

    return 0;

}

Determines if a number is prime by checking divisibility up to square root. Shows optimization in prime checking.

#include <stdio.h>

int main() {
    printf("Name: Saurav\n");
    printf("Address: Nepal\n");
    printf("Age: 21\n");
    return 0;
}

Prints personal details like name, address, and age using printf statements.

#include <stdio.h>

int main() {
    printf("This is a basic C program\n");
    return 0;
}

Demonstrates the basic structure of a C program.

#include <stdio.h>

int main() {
    int a = 10;
    printf("Value of a: %d\n", a);
    return 0;
}

Contains a syntax error for debugging practice.

#include <stdio.h>

int main() {
    int l = 10, b = 5;
    int area = l + b;
    printf("Area = %d\n", area);
    return 0;
}

Program runs but gives incorrect output due to logical error.

#include <stdio.h>

int main() {
    int a = 10, b = 0;
    int c = a / b;
    printf("Result = %d\n", c);
    return 0;
}

Demonstrates runtime error caused by division by zero.

#include <stdio.h>

/*
    Program Name: Simple Addition
    Description: Adds two integers
    Author: Student
*/

int main() {
    int a = 5, b = 7;
    int sum = a + b;
    printf("Sum = %d\n", sum);
    return 0;
}

Demonstrates use of comments and documentation in C.