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isunordered

From cppreference.com
< c‎ | numeric‎ | math
 
 
 
Common mathematical functions
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isunordered
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Macro constants
 
Defined in header <math.h>
#define isunordered(x, y) /* implementation defined */
(since C99)

Determines if the floating point numbers x and y are unordered, that is, one or both are NaN and thus cannot be meaningfully compared with each other.

Contents

[edit] Parameters

x - floating point value
y - floating point value

[edit] Return value

Nonzero integral value if either x or y is NaN, 0 otherwise


[edit] Example

#include <stdio.h>
#include <math.h>
 
int main(void)
{
    printf("isunordered(NAN,1.0) = %d\n", isunordered(NAN,1.0));
    printf("isunordered(1.0,NAN) = %d\n", isunordered(1.0,NAN));
    printf("isunordered(NAN,NAN) = %d\n", isunordered(NAN,NAN));
    printf("isunordered(1.0,0.0) = %d\n", isunordered(1.0,0.0));
 
    return 0;
}

Possible output:

isunordered(NAN,1.0) = 1
isunordered(1.0,NAN) = 1
isunordered(NAN,NAN) = 1
isunordered(1.0,0.0) = 0

[edit] See also

classifies the given floating-point value
(function) [edit]
(C99)
checks if the given number is NaN
(function) [edit]
C++ documentation for isunordered