Home / Tips / Programming languages / Scripting languages / JavaScript / How to check if a variable is undefined in JavaScript

How to check if a variable is undefined in JavaScript

JavaScript
 
JavaScript
  • Currently 0 out of 5 Stars.
  • 1
  • 2
  • 3
  • 4
  • 5
Rating: 0/5 (0 votes cast)

Thank you for rating!

You have already rated this page, you can only rate it once!

Your rating has been changed, thanks for rating!

Log in or create a user account to rate this page.


The proper way to check if a variable exists in JavaScript. The following code does it:

if( typeof yourVariable === 'undefined' ) {
  // Your variable is undefined
}

 

Read also

Post comment

basicuse.net
html5_css
106160485398655174790

Quick navigation

General navigation