isnan

Is a macro that determines whether an argument value is a NaN (not a number).

Library:LibC

Classification:ANSI

Service:Math

Syntax

  #include <math.h> 
   
  isnan ( x );

Parameters

x: (IN) Specifies the argument.

Return Values

If the value is a NaN, returns a nonzero value. Otherwise, returns 0.

Remarks

The macro can be used with double, float, and long double arguments.

See Also