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# copysign

From cppreference.com
< c‎ | numeric‎ | math

Defined in header `<math.h>` |  |
float copysignf( float x, float y ); |  | (since C99)
double copysign( double x, double y ); |  | (since C99)
long double copysignl( long double x, long double y ); |  | (since C99)

Composes a floating point value with the magnitude of `x` and the sign of `y`.

### [edit] Parameters

x, y | - | floating point values

### [edit] Return value

Floating point value with the magnitude of `x` and the sign of `y`

### [edit] Example

Run this code

    #include <stdio.h>
    #include <math.h>

    int main(void)
    {
        printf("copysign(1.0,+2.0)      = %+.1f\n", copysign(1.0,+2.0));
        printf("copysign(1.0,-2.0)      = %+.1f\n", copysign(1.0,-2.0));
        printf("copysign(INFINITY,-2.0) = %f\n",    copysign(INFINITY,-2.0));
        printf("copysign(NAN,-2.0)      = %f\n",    copysign(NAN,-2.0));

        return 0;
    }

Possible output:

    copysign(1.0,+2.0)      = +1.0
    copysign(1.0,-2.0)      = -1.0
    copysign(INFINITY,-2.0) = -inf
    copysign(NAN,-2.0)      = -nan

### [edit] See also

fabsfabsffabsl (C99)(C99) | computes absolute value of a floating-point value (|x|) (function) [edit]
signbit (C99) | checks if the given number is negative (function) [edit]
C++ documentation for copysign

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