JavaScript isNaN() Function
 JavaScript Global Functions
Definition and Usage
The isNaN() function determines whether a value is an illegal number (Not-a-Number).
This function returns true if the value is NaN, and false if not.
Syntax
| Parameter |
Description |
| value |
Required. The value to be tested |
Browser Support
The isNaN() function is supported in all major browsers.
Example
Example
Check whether a number is an illegal number:
<script type="text/javascript">
document.write(isNaN(123)+ "<br />");
document.write(isNaN(-1.23)+ "<br />");
document.write(isNaN(5-2)+ "<br />");
document.write(isNaN(0)+ "<br />");
document.write(isNaN("Hello")+ "<br />");
document.write(isNaN("2005/12/12")+ "<br />");
</script>
|
The output of the code above will be:
false
false
false
false
true
true
|
Try it yourself »
|
JavaScript Global Functions
Whether you're new to XML or already an advanced user,
the user-friendly views and powerful entry helpers,
wizards, and debuggers in XMLSpy are designed to meet your XML
and Web development needs from start to finish.
New features in Version 2010!
- XML editor
- Graphical XML Schema / DTD editors
- XSLT 1.0/2.0 editor, debugger, profiler
- XQuery editor, debugger, profiler
- XBRL validator, taxonomy editor, taxonomy wizard
- Support for Office Open XML (OOXML)
- Graphical WSDL 1.1/2.0 editor & SOAP debugger
- JSON editing & conversion
- Java, C#, C++ code generation
- And much more!
Download a free trial today!
|
|
|
|
