C Tutorial/math.h/copysign
copysign
Item Value Header file math.h Declaration float copysignf(float val, float signval);double copysign(double val, double signval);long double copysignl(long double val, long double signval); Function gives val the same sign as signval, and return the result.
#include <math.h>
#include <stdio.h>
int main(void)
{
printf("%f", copysignf(1.0, -2.0));
}