From http://www.w3schools.com (Copyright Refsnes Data)

JavaScript isFinite() Function

Function Reference JavaScript Functions

Definition and Usage

The isFinite() function is used to check if a value is a finite, legal number.

Syntax

isFinite(value)

Parameter Description
value Required. The value to be tested

Example

Example

Check for finite numbers:

<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>

The output of the code above will be:

true
true
true
true
false
false

Try it yourself »

Function Reference JavaScript Functions

From http://www.w3schools.com (Copyright Refsnes Data)