# abs() in C - Source Code Example

In this source code example, we will see how to use the abs() function in C programming with an example.

## abs() Function Overview

The abs() function is available in <stdlib.h>, returns the absolute value of an integer. In simpler terms, if you provide a negative integer, it gives back the positive version of it. If the integer is already positive or zero, it remains unchanged.

## Source Code Example

``````#include <stdio.h>
#include <stdlib.h>

int main() {
// Define some sample numbers
int num1 = -5, num2 = 13, num3 = 0;

// Calculate absolute values using abs() function
int absNum1 = abs(num1);
int absNum2 = abs(num2);
int absNum3 = abs(num3);

printf("Absolute value of %d is %d\n", num1, absNum1);
printf("Absolute value of %d is %d\n", num2, absNum2);
printf("Absolute value of %d is %d\n", num3, absNum3);

return 0;
}
``````

## Output

```Absolute value of -5 is 5
Absolute value of 13 is 13
Absolute value of 0 is 0
```

## Explanation

1. Three integer variables num1, num2, and num3 are declared with values -5, 13, and 0 respectively.

2. We then calculate the absolute values for each of these numbers using the abs() function.

3. The results are printed out, demonstrating how abs() behaves with negative, positive, and zero values.