ActionScript: The Definitive Guide

Name

isFinite( ) Global Function — check if a number is less than Infinityand greater than -Infinity

Availability

Flash 5

Synopsis

isFinite(number)

Arguments

number

Any numeric value or expression that yields a numeric value.

Returns

A Boolean value; true if the number falls between Number.MAX_VALUE and -Number.MAX_VALUE (inclusive), false if not. If number does not belong to the number datatype, number is converted to the number type before isFinite( ) executes.

Description

The isFinite( ) function simply checks if a number is in the legal numeric value range of ActionScript. Use isFinite( ) before executing code that requires a legitimate number to operate properly.

Example

if (!isFinite(x * y)) {           // Test if the number is not finite
  trace ("The answer is too large to display. Try again.");
}
isFinite(-2342434);              // Yields true
isFinite(Math.PI);               // Yields true
isFinite(Number.MAX_VALUE * 2)   // Yields false

See Also

-Infinity, Infinity, isNan( ), Number.MAX_VALUE, Number.MIN_VALUE; Section 4.3.3 in Chapter 4