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_isnan (Windows CE 5.0)

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Developing an Application > Microsoft C Run-time Library for Windows CE > Run-time Library Reference

Checks given double-precision floating-point value for not a number (NaN).

int _isnan(    doublex);

Parameters

  • x
    Double-precision floating-point value.

Return Values

_isnan returns a nonzero value if the argument x is a NaN; otherwise it returns 0.

Remarks

The _isnan function tests a given double-precision floating-point value x, returning a nonzero value if x is a NaN.

A NaN is generated when the result of a floating-point operation cannot be represented in Institute of Electrical and Electronics Engineers (IEEE) format.

For information about how a NaN is represented for output, see printf.

Requirements

OS Versions: Windows CE 2.0 and later.
Header: stdlib.h.
Link Library: coredll.dll.

See Also

_finite | _fpclass

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