Skip to content
Related Articles

Related Articles

Improve Article

Underscore.js _.uniqueId() Function

  • Last Updated : 15 Oct, 2020

Underscore.js is a JavaScript library that provides a lot of useful functions that help in the programming in a big way like the map, filter, invoke, etc even without using any built-in objects.

The _.uniqueId() function is an inbuilt function in Underscore.js library of JavaScript which is used to generate a globally unique id for the client-side models or the DOM elements which requires one. When a prefix is passed as an argument to this method, the id generated will be appended to it.

Hey geek! The constant emerging technologies in the world of web development always keeps the excitement for this subject through the roof. But before you tackle the big projects, we suggest you start by learning the basics. Kickstart your web development journey by learning JS concepts with our JavaScript Course. Now at it's lowest price ever!

Syntax:

_.uniqueId( prefix )

Parameters: It accepts a single parameter as mentioned above and described below:



  • prefix: It is the prefix that would be appended to the id It is am optional parameter.

Return Value: This method returns a globally unique id.

Example 1:

HTML




<!DOCTYPE html>
<html>
  
<head>
    <script src=
    </script>
</head>
  
<body>
    <script type="text/javascript">
  
        // Using _.uniqueId() method 
        // with its parameter
        console.log(_.uniqueId('gfG_'));
        console.log(_.uniqueId('Geeks_'));
        console.log(_.uniqueId('CS_'));
    </script>
</body>
  
</html>

Output:

gfG_1
Geeks_2
CS_3

Example 2:

HTML




<!DOCTYPE html>
<html>
  
<head>
    <script src=
    </script>
</head>
  
<body>
    <script type="text/javascript">
  
        // Using a loop
        for (i = 3; i < 100; i *= 2) {
  
            // Calling uniqueId method
            // without any parameter   
            console.log(_.uniqueId());
        }
    </script>
</body>
  
</html>

Output:

1
2
3
4
5
6



My Personal Notes arrow_drop_up
Recommended Articles
Page :