JavaScript generates a unique id | 3 Ways with examples code

How to Generate Unique ID in JavaScript?

Using UUID module or Math.random method or Date.now method can generate a unique identifier (id) in JavaScript.

JavaScript generates a unique id Examples

Let’s see all ways example in HTML and JS:-

Using UUID library

To create a random UUID…

1. Install

npm install uuid

2. Create a UUID (ES6 module syntax)

import { v4 as uuidv4 } from 'uuid';
uuidv4(); // ⇨ '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'

… or using Common JS syntax:

<!-- wp:paragraph -->
<p>… or using CommonJS syntax:</p>
<!-- /wp:paragraph -->

Read more: https://www.npmjs.com/package/uuid

Another solution

<!DOCTYPE html>
<html> 
<body>

    <script type="text/javascript">
       function create_UUID(){
        var dt = new Date().getTime();
        var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
            var r = (dt + Math.random()*16)%16 | 0;
            dt = Math.floor(dt/16);
            return (c=='x' ? r :(r&0x3|0x8)).toString(16);
        });
        return uuid;
    }

    console.log(create_UUID());
</script>

</body>
</html>

Output:

JavaScript generates a unique id UUID

Math.random built-in function

This example will return a unique combination of numbers.

<script type="text/javascript">
    var uid = Math.floor(Math.random() * 100)

    console.log(uid);
</script>

Output: 19

Date.now another JavaScript built-in function

Using this way will return number of miliseconds elapsed since January 1, 1970.

<!DOCTYPE html>
<html> 
<body>

    <script type="text/javascript">
        var uid = Date.now()

        console.log(uid);
    </script>

</body>
</html>

Output:

Do comment if you have any questions or suggestion on this topic.

Note: All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version


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