Fabs in c: The function double fabs(double x); returns the absolute value of x(|x|). If x is a negative number then it returns the positive equivalent of x by multiplying it with -1.
Function prototype of fabs
double fabs(double x);
- x : A floating point value whose absolute value to be returned.
Return value of fabs
It returns the absolute value of x(|x|).
C program using fabs function
The following program shows the use of fabs function to calculate absolute value of a number.

#include <stdio.h>
#include <math.h>
int main ()
{
double x, result;
printf("Enter a number\n");
scanf("%lf", &x);
result = fabs(x);
printf("Absolute value of %lf is %lf\n", x, result);
return 0;
}
Output
Enter a number -123 Absolute value of -123.000000 is 123.000000
Enter a number 0 Absolute value of 0.000000 is 0.000000
Enter a number 123 Absolute value of 123.000000 is 123.000000