w3resource

JavaScript: Generate a UUID in Node.JS.

JavaScript fundamental (ES6 Syntax): Exercise-254 with Solution

Write a JavaScript program to generate a UUID in Node.JS. Use crypto API to generate a UUID, compliant with RFC4122 version 4.

  • Use crypto.randomBytes() to generate a UUID, compliant with RFC4122 version 4.
  • Use Number.prototype.toString(16) to convert it to a proper UUID.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const crypto = require('crypto');
const UUIDGeneratorNode = () =>
  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
    (c ^ (crypto.randomBytes(1)[0] & (15 >> (c / 4)))).toString(16)
  );
console.log(UUIDGeneratorNode());

Flowchart:

flowchart: Generate a UUID in Node.JS. Use crypto API to generate a UUID, compliant with RFC4122 version 4.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program to generate a UUID in a browser.
Next: Write a JavaScript program that will return true if the provided predicate function returns true for at least one element in a collection, false otherwise.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



JavaScript: Tips of the Day

How to check whether a string contains a substring in JavaScript?

ECMAScript 6 introduced String.prototype.includes:

const string = "foo";
const substring = "oo";

console.log(string.includes(substring));

includes doesn't have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns -1 when a substring cannot be found: 

var string = "foo";
var substring = "oo";

console.log(string.indexOf(substring) !== -1);

Ref: https://bit.ly/3fFFgZv