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