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isnormal

From cppreference.com
< c‎ | numeric‎ | math
 
 
 
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Defined in header <math.h>
#define isnormal(arg) /* implementation defined */
(since C99)

Determines if the given floating point number arg is normal, i.e. is neither zero, subnormal, infinite, nor NaN. The macro returns an integral value.

FLT_EVAL_METHOD is ignored: even if the argument is evaluated with more range and precision than its type, it is first converted to its semantic type, and the classification is based on that.

Contents

[edit] Parameters

arg - floating point value

[edit] Return value

Nonzero integral value if arg is normal, 0 otherwise.

[edit] Example

#include <stdio.h>
#include <math.h>
#include <float.h>
 
int main(void)
{
    printf("isnormal(NAN)         = %d\n", isnormal(NAN));
    printf("isnormal(INFINITY)    = %d\n", isnormal(INFINITY));
    printf("isnormal(0.0)         = %d\n", isnormal(0.0));
    printf("isnormal(DBL_MIN/2.0) = %d\n", isnormal(DBL_MIN/2.0));
    printf("isnormal(1.0)         = %d\n", isnormal(1.0));
}

Output:

isnormal(NAN)         = 0
isnormal(INFINITY)    = 0
isnormal(0.0)         = 0
isnormal(DBL_MIN/2.0) = 0
isnormal(1.0)         = 1

[edit] References

  • C11 standard (ISO/IEC 9899:2011):
  • 7.12.3.5 The isnormal macro (p: 237)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.12.3.5 The isnormal macro (p: 217-218)

[edit] See also

classifies the given floating-point value
(function macro) [edit]
checks if the given number has finite value
(function macro) [edit]
(C99)
checks if the given number is infinite
(function macro) [edit]
(C99)
checks if the given number is NaN
(function macro) [edit]
C++ documentation for isnormal