💡 Sample Code-Based Questions with Explanations

🧾 Q1: Write a program to reverse a number.

c

CopyEdit

#include <stdio.h>

int main() {

    int n, rev = 0, r;

    printf(“Enter a number: “);

    scanf(“%d”, &n);

    while (n != 0) {

        r = n % 10;

        rev = rev * 10 + r;

        n /= 10;

    }

    printf(“Reversed Number: %d”, rev);

    return 0;

}

💬 Explanation: This code uses modulus and division to extract digits and reverse the number.

🧾 Q2: Write a program to calculate factorial using recursion.

c

CopyEdit

#include <stdio.h>

int factorial(int n) {

    if (n == 0) return 1;

    return n * factorial(n – 1);

}

int main() {

    int num;

    printf(“Enter a number: “);

    scanf(“%d”, &num);

    printf(“Factorial = %d”, factorial(num));

    return 0;

}