In this tutorial, we are going to learn new program which is **Swapping of two numbers** and most commonly used in exams or in interviews.

Implementation of this program is very simple.

What is swapping: **Swapping of two numbers** means replacing the numbers.

How to swap two numbers using the third variable?

For swapping number first we have 2 numbers and using the third variable we swap numbers by doing following steps

Steps for swapping using the third variable

Take two variable with numbers stores in it and one-third variable (a temporary variable )

**Variable a, b, temp**

1. Copy first variable value in a temporary variable.

temp = a

2. Copy the second variable value in the first variable.

a = b

3. Copy temporary variable value to the first variable.

b = temp

**Example**

First number = 10

Second number = 20

Temp number

Now swap numbers using above steps

**Temp number = First number**

=> Temp number = 10

**First number = second number**

=> First number = 20

**Second number = Temp number**

=> second number = 10

We got the swapped number as,

**First number = 20**

**Second number = 10**

In this way, we implement swapping of two numbers using the third variable

### C program swap two number using the third variable

123456789101112131415161718192021222324252627 | #include<stdio.h>void main(){int first,second,temp; //declaring variableprintf(“Enter first\n”);scanf(“%d”,&first); // take input first numberprintf(“Enter second \n”);scanf(“%d”,&second); //take second number inputprintf(“before swaping\n first = %d \n second = %d \n”,first ,second );temp = first ;first = second;second = temp;printf(“after swaping\n first = %d \n second =%d”,first,second);} |

**Output :**

**Explanation**

**1. First Here we initialized first, second and temp variable**

first –> for storing 1st number

second –>for storing the second number

temp ->for storing temporary variable

**2. Now here goes the logic(let us take first=10 and second=20)**

temp = first , Therefore, temp =10

first = second , Therefore first = 20

second = temp, Therefore second =10

**3. Now the values of first and second are 20 and 10**

**4. The values of first and second after swapping are printed.**

**Other C language solved programs**