JavaScript UUID Regex

To match a UUID (also known as a universally unique identifier) using a regular expression in JavaScript, you can use the following regex pattern:

/^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i
Code language: ReasonML (reasonml)

And here is an example using this regex in JavaScript:

const regex = new RegExp('^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$', 'i');

// Create a UUID using the crypto library
// Example: '7a02a57e-1dbc-4219-83eb-c7d1c99865ac'
let uuid = crypto.randomUUID();

// Test if the regex matches the UUID
const matches = regex.test(uuid);

// Prints: true
console.log(matches);
Code language: JavaScript (javascript)

isUUID Function

To create a function that checks if the provided value is a UUID, we can wrap the code above into a function:

function isUUID(value) {
  const regex = new RegExp('^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$', 'i');

  return regex.test(value);
}
Code language: JavaScript (javascript)

UUID Regex Detail

This regular expression uses the following rules:

• The ^ and $ characters are used to match the start and end of the string, respectively, ensuring that the entire string is matched and not just a substring.
• The pattern is surrounded by square brackets ([ and ]), which indicate a character class. This means that the regular expression will match any of the characters within the brackets.
• The 0-9 and a-f characters within the character class specify a range of characters. This means that the regular expression will match any digit from 0 to 9, and any lowercase letter from a to f.
• The {n} notation after each character class specifies a repetition count. This means that the regular expression will match exactly n occurrences of the character class. For example, {8} means that the regular expression will match exactly eight characters from the character class.
• The - character is included within the character class to match the hyphen character that separates the different sections of a UUID.
• The 1-5 and 89ab characters within the character class are used to match specific patterns in the UUID. These patterns are match UUID versions 1-5.

Creating a UUID in JavaScript

In JavaScript, the crypto.randomUUID() method generates a random Universal Unique Identifier (UUID) in the standard format.

A UUID is a unique identifier that is often used to identify records in a database, or to identify devices and other objects in a network.

Here’s an example of how to use the crypto.randomUUID() method in JavaScript:

// Generate a random UUID
var uuid = crypto.randomUUID();

// Print the UUID to the console
console.log(uuid);
Code language: JavaScript (javascript)

Keep in mind that the crypto.randomUUID() method is not supported in all browsers, so you’ll need to check for browser compatibility before using it in your code.