C++ cstdlib abs()

#include <iostream>
#include <cstdlib>
using namespace std;

int main() {

  // get absolute value of -5
  cout << abs(-5);

  return 0;
}

// Output: 5

abs() Syntax

The syntax of the abs() function is:

abs(int num);

abs() Parameters

The abs() function takes the following parameters:

• num: An integral value whose absolute value is returned. The number can be:
  • int
  • long
  • long long

abs() Return Value

The abs() function returns:

• the absolute value of num i.e. |num|
• the positive value if the specified number is negative

abs() Prototypes

The prototypes of abs() as defined in the cstdlib header file are:

int abs(int num);

long abs(long num);

long long abs(long long num);

abs() Overloading

The abs() function is also overloaded in:

• cmath header file for floating-point types
• complex header file for complex numbers
• valarray header file for valarrays

Example: C++ abs()

#include <iostream>
#include <cstdlib>
using namespace std;

int main() {
  int x = -5;
  long y = -2371041;

  int a = abs(x);
  long b = abs(y);

  cout << "abs(" << x << ") = |" << x << "| = " << a << endl;
  cout << "abs(" << y << ") = |" << y << "| = " << b;

  return 0;
}

Output

abs(-5) = |-5| = 5
abs(-2371041) = |-2371041| = 2371041