Constants are immutable variables which value cannot be changed. Once, you have created a constant, its value cannot be changed.

image

While coding in JavaScript, many times you may have come across a requirement to create constants. Before ECMA Script 6, it was not very easy to create constants in JavaScript. In this post, I will show you to create constants in both ECMA Script 5 and ECMA Script 6.

Constants in ECMA 5

We can create a constant in ECMA Script 5 using Object.defineProperty(). First we need to find out, whether variable would be a global variable or part of the window object. Once that is determined, create variable by setting writable to false.

Object.defineProperty() function takes three parameters,

  1. Object for which variable should be created
  2. Name of the variable to be created
  3. Object to configure behavior of the variable.

Read full article on the Infragistics blog

Advertisements

Published by Dhananjay Kumar

Dhananjay kumar is an independent trainer , a consultant and a programmer from India. He has mentored more than 1000 professionals and known for his unique way of teaching. He has been part of the multiple projects for big clients. He is a well known blogger and speaker. He has been awarded Microsoft MVP award 5 times in a row. For more you can reach him at debugmode[at]outlook[dot]com

Leave a Reply

Fill in your details below or click an icon to log in:

Gravatar
WordPress.com Logo

You are commenting using your WordPress.com account. ( Log Out / Change )

Twitter picture

You are commenting using your Twitter account. ( Log Out / Change )

Facebook photo

You are commenting using your Facebook account. ( Log Out / Change )

Google+ photo

You are commenting using your Google+ account. ( Log Out / Change )

Cancel

Connecting to %s