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JavaScript: Generate a UUID in a browser

JavaScript fundamental (ES6 Syntax): Exercise-253 with Solution

Generate UUID (Browser)

Write a JavaScript program to generate a UUID in a browser.

  • Use Crypto.getRandomValues() 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 
// Define a function 'UUIDGeneratorBrowser' to generate a UUID (Universally Unique Identifier) in a web browser environment
const UUIDGeneratorBrowser = () =>
  // Generate a UUID using a random number generator provided by the browser's crypto API
  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
    // For each character 'c' in the UUID template, replace it with a randomly generated hexadecimal digit
    (c ^ (crypto.getRandomValues(new Uint8Array(1))[0] & (15 >> (c / 4)))).toString(16)
  );

// Generate and log a UUID using the 'UUIDGeneratorBrowser' function
console.log(UUIDGeneratorBrowser());

Output:

a47704c1-b9cb-481d-bada-bd6495a88ef7

Flowchart:

flowchart: Generate a UUID in a browser.

Live Demo:

See the Pen javascript-basic-exercise-253-1 by w3resource (@w3resource) on CodePen.


For more Practice: Solve these Related Problems:

  • Write a JavaScript program that generates a version 4 UUID using the browser’s crypto.getRandomValues() API.
  • Write a JavaScript function that creates a UUID compliant with RFC4122 using random bytes from the browser.
  • Write a JavaScript program that constructs a UUID string by replacing template placeholders with random hex digits.
  • Write a JavaScript function that verifies the format of a generated UUID and logs whether it is valid.

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