JavaScript isFinite() Function

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# JavaScript isFinite() Function

JavaScript Global Functions

## Example

Check whether a number is a finite, legal number:

var a = isFinite(123) + "<br>";
var b = isFinite(-1.23) + "<br>";
var c = isFinite(5-2) + "<br>";
var d = isFinite(0) + "<br>";
var e = isFinite("Hello") + "<br>";
var f = isFinite("2005/12/12") + "<br>";
var res = a + b + c + d + e + f;

The result of res will be:

true
true
true
true
false
false
Try it yourself »

## Definition and Usage

The isFinite() function determines whether a number is a finite, legal number.

This function returns false if the value is +infinity, -infinity, or NaN (Not-a-Number), otherwise it returns true.

## Browser Support

The isFinite() function is supported in all major browsers.

## Syntax

isFinite(value)

## Parameter Values

Parameter | Description
--- | ---
value | Required. The value to be tested

## Return Value

Type | Description
--- | ---
Boolean | Returns "false" if the value is +infinity, -infinity, or NaN, otherwise it returns true.

## Technical Details

JavaScript Version: | 1.3

JavaScript Global Functions

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