Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Mail Systems
Eclipse Documentation

How To Guides
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Problem Solutions
Privacy Policy




The JavaScript FAQ
Prev Home Next

Number vs. String

Question: Is there a way to test whether a particular variable holds a number or a string?

Answer: Yes. To test whether the variable holds a number or a string, use the typeof operator. If your variable holds a number, typeof(variable) will return "number". If it holds a string, typeof(variable) will return "string". The following are examples of typeof usage:

typeof(123)    // result: "number"
typeof("123")  // result: "string"

if (typeof k == "string") { alert('k is a string.') }
if (typeof k == "number") { alert('k is a number.') }
The typeof operator can also help you distinguish between other data types. Depending on the particular variable's value, the result of typeof can be one of the following:
    "undefined" Copyright © 1999-2006, Alexei Kourbatov

The JavaScript FAQ
Prev Home Next

  Mirrored with kind permission of Alexei Kourbatov Design by Interspire