G-L > isNaN

isNaN

isnan

Availability

Flash Player 5.

Usage

isNaN(expression)

Parameters

expression A Boolean, variable, or other expression to be evaluated.

Returns

A Boolean value.

Description

Top-level function; evaluates the parameter and returns true if the value is not a number (NaN), indicating the presence of mathematical errors.

Example

The following code illustrates return values for the isNan function.

isNan("Tree")

// returns true

isNan(56)

// returns false

isNaN(Number.POSITIVE_INFINITY)
// returns false