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# What is abs() in C++?

Kainat Asif

The abs() function in C++ is used to get the absolute value of a number. The absolute value of a number is the distance of the number from 0. In other words, it is the non-negative value of the number. The absolute value of a number x is represented as |x| as shown below:

## Library

To use the abs() function, include the following library:

#include <cstdlib>


## Declaration

The abs() function is declared as:

int abs(int x);


Or

long int abs(long int x );


Or

long long int abs(long long int x);

• x: The number whose absolute value will be calculated.

## Return value

The abs() function returns the absolute value of x.

## abs() for floating-point types

The abs() function in the cstlib header file computes the absolute value of integer data type i.e. int. To calculate the absolute value of floating-point types, the abs() function is overloaded in the library cmath. The abs() function in cmath header file is declared as:

double abs (double x);


Or

float abs (float x);


Or

long double abs (long double x);


Or

double abs (T x);


## Examples

### Example 1

Consider the code snippet below, which demonstrates the use of the abs() function:

#include <cstdlib>
#include <iostream>

using namespace std;

int main()
{
int x1 = -4;
int x2 = 0;
int x3 = 4;

int abs1 = abs(x1);
cout<< "abs ( "<<x1<<" ) = "<<abs1<<endl;

int abs2 = abs(x2);
cout<< "abs ( "<<x2<<" ) = "<<abs2<<endl;

int abs3 = abs(x3);
cout<< "abs ( "<<x3<<" ) = "<<abs3<<endl;

return 0;
}

### Explanation

Three integers x1, x2, and x3 are declared in line 8-10. The abs() function is used in line 12, line 15, and line 18 to calculate the absolute value of x1, x2, and x3 respectively.

### Example 2

Consider the code snippet below, which demonstrates the use of the abs() function from cmath header file:

#include <cmath>
#include <iostream>

using namespace std;

int main()
{
float x1 = -4.4;
float x2 = 0;
float x3 = 4.9;

float abs1 = abs(x1);
cout<< "abs ( "<<x1<<" ) = "<<abs1<<endl;

float abs2 = abs(x2);
cout<< "abs ( "<<x2<<" ) = "<<abs2<<endl;

float abs3 = abs(x3);
cout<< "abs ( "<<x3<<" ) = "<<abs3<<endl;

return 0;
}

### Explanation

Three floats x1, x2, and x3 are declared in line 8-10. The abs() function is used in line 12, line 15, and line 18 to calculate the absolute value of x1, x2, and x3 respectively.

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Kainat Asif