JS & DOM Reference
OverviewJavaScript Objects
JS ArrayJS Boolean
JS Date
JS Math
JS Number
JS String
JS RegExp
JS Global
Browser Objects
WindowNavigator
Screen
History
Location
Core DOM Objects
DOM NodeDOM NodeList
DOM NamedNodeMap
DOM Document
DOM Element
DOM Attr
HTML DOM Objects
DOM DocumentDOM Events
DOM Elements
DOM Anchor
DOM Area
DOM Base
DOM Body
DOM Button
DOM Form
DOM Frame/IFrame
DOM Frameset
DOM Image
DOM Input Button
DOM Input Checkbox
DOM Input File
DOM Input Hidden
DOM Input Password
DOM Input Radio
DOM Input Reset
DOM Input Submit
DOM Input Text
DOM Link
DOM Meta
DOM Object
DOM Option
DOM Select
DOM Style
DOM Table
DOM td / th
DOM tr
DOM Textarea
JavaScript isFinite() Function
JavaScript Global Functions
Definition and Usage
The isFinite() function determines whether a number is a finite, legal number.
Tip: This function returns false if the value is +infinity, -infinity, or NaN.
Syntax
isFinite(value)
| Parameter | Description |
|---|---|
| value | Required. The value to be tested |
Browser Support
The isFinite() function is supported in all major browsers.
Example
Example
Check whether a number is a finite, legal number:
<script type="text/javascript">
document.write(isFinite(123)+ "<br />");
document.write(isFinite(-1.23)+ "<br />");
document.write(isFinite(5-2)+ "<br />");
document.write(isFinite(0)+ "<br />");
document.write(isFinite("Hello")+ "<br />");
document.write(isFinite("2005/12/12")+ "<br />");
</script>
document.write(isFinite(123)+ "<br />");
document.write(isFinite(-1.23)+ "<br />");
document.write(isFinite(5-2)+ "<br />");
document.write(isFinite(0)+ "<br />");
document.write(isFinite("Hello")+ "<br />");
document.write(isFinite("2005/12/12")+ "<br />");
</script>
The output of the code above will be:
true
true
true
true
false
false
true
true
true
false
false
Try it yourself »
JavaScript Global Functions
| WEB HOSTING |
|---|
| Best Web Hosting |
| PHP MySQL Hosting |
| Best Hosting Coupons |
| UK Reseller Hosting |
| Cloud Hosting |
| Top Web Hosting |
| $7.95/mo SEO Hosting |
| Premium Website Design |
| WEB BUILDING |
|---|
| Download XML Editor |
| FREE Website BUILDER |
| Free Website Templates Free CSS Templates |
| Make Your Own Website |
| W3SCHOOLS EXAMS |
|---|
|
Get Certified in: HTML, CSS, JavaScript, XML, PHP, and ASP |
| W3SCHOOLS BOOKS |
|---|
|
New Books: HTML, CSS JavaScript, and Ajax |
| STATISTICS |
|---|
|
Browser Statistics Browser OS Browser Display |
| SHARE THIS PAGE |
|---|
W3Schools is optimized for learning, testing, and training. Examples might be simplified to improve reading and basic understanding.
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2012 by Refsnes Data. All Rights Reserved.
Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2012 by Refsnes Data. All Rights Reserved.