# isFinite

#### Availability

Flash Player 5.

#### Usage

    isFinite(expression)

#### Parameters

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

#### Returns

A Boolean value.

#### Description

Top-level function; evaluates the `expression` and returns `true` if it is a finite number, and `false` if it is infinity or negative infinity. The presence of infinity or negative infinity indicates a mathematical error condition such as division by 0.

#### Example

The following are examples of return values for `isFinite`:

    isFinite(56)
    // returns true

    isFinite(Number.POSITIVE_INFINITY)
    // returns false