C Program to Swap Two Numbers Using Temporary Variable

In this tutorial, we will learn how to swap two numbers in C programming using a temporary variable. This is one of the most common beginner-level programs in C.

Concept Overview

Swapping means exchanging the values of two variables. In this method, a third variable (temporary variable) is used to store one value while the exchange takes place.

Program

#include <stdio.h>

int main() {
    int a, b, temp;

    printf("Enter 2 numbers: ");
    scanf("%d %d", &a, &b);

    // Swapping using temporary variable
    temp = a;
    a = b;
    b = temp;

    printf("After swapping: %d %d\n", a, b);

    return 0;
}

Output

Enter 2 numbers: 10 20
After swapping: 20 10

Explanation

• `int a, b, c;` – Declares three integer variables.
• `scanf("%d %d", &a, &b);` – Takes input from the user.
• `c = a;` – Stores the value of `a` in the temporary variable `c`.
• `a = b;` – Assigns the value of `b` to `a`.
• `b = c;` – Assigns the stored value from `c` to `b`.
• After these steps, the values of `a` and `b` are successfully swapped.