signbit

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signbit
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Macro constants
 
Defined in header <math.h>
#define signbit(arg) /* implementation defined */
(since C99)

Determines if the given floating point number arg is negative. The macro returns an integral value.

Contents

[edit] Parameters

arg - floating point value

[edit] Return value

Nonzero integral value if arg is negative, 0 otherwise

[edit] Example

#include <stdio.h>
#include <math.h>
#include <float.h>
 
int main(void)
{
    printf("signbit(+0.0) = %d\n", signbit(+0.0));
    printf("signbit(-0.0) = %d\n", signbit(-0.0));
 
    return 0;
}

Possible output:

signbit(+0.0) = 0
signbit(-0.0) = 128

[edit] See also

(C99)(C99)
computes absolute value of a floating-point value (|x|)
(function)
produces a value with the magnitude of a given value and the sign of another given value
(function)
C++ documentation for signbit