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# C Program to swap two numbers

### Write a Program to Swap Two Numbers in C without third Variable

Swapping two number in C programming language defines the exchange values of two variables. Let’s suppose you have two variable X & Y. Value of X is 15 & value of Y is 25. So, after swapping the value, X will become 25 & Y will become 15.

### Program to swap two numbers without third variable

You can swap two numbers without using third variable

Let's take an example

```#include<stdio.h>
int main()
{
int x=10, y=20;
printf("Before swaped number  x=%d y=%d",x,y);
x=x+y;//a=30 (10+20)
y=x-y;//y=10 (30-20)
x=x-y;//x=20 (30-10)
printf("\nAfter swaped Number  x=%d y=%d",x,y);
return 0;
}
```
Output :
Before swaped number x=10 y=20
After swaped Number x=20 y=10

### C Program to swap two numbers using third variable

```#include<stdio.h>
int main()
{
int x=10, y=20,z=0;
printf("Before swaped number  x=%d y=%d",x,y);
z=x;
x=y;
y=z;
printf("\nAfter swaped Number  x=%d y=%d",x,y);
return 0;
}
```
Output :
Before swaped number x=10 y=20
After swaped Number x=20 y=10