There are three ways to generate UUIDs in JavaScript: 1. Use the crypto module to generate a secure UUID in the Node.js environment, which is suitable for high-security scenarios; 2. Use Math.random() in the browser environment to implement simple UUIDs, suitable for non-security sensitive purposes; 3. Use third-party library uuid, which is recommended for production environments to ensure compatibility and correctness.
Generating a GUID (global unique identifier) or UUID (general unique identifier) in JavaScript usually refers to generating a string that conforms to the UUID standard format, such as xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx . Although JavaScript native does not directly provide a method to generate UUIDs, we can use some tricks to achieve it.
Using crypto module (Node.js environment)
If you are developing in a Node.js environment, you can use the built-in crypto module to generate a secure UUID:
const crypto = require('crypto');
function generateUUID() {
return 'xxxxxxx-xxxx-4xxx-yxxxx-xxxxxxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
const r = (crypto.randomBytes(1)[0] & 0x0f) | 0x10;
const v = c === 'x' ? r : (r & 0x3) | 0x8;
return v.toString(16);
});
} This code uses crypto.randomBytes to generate safer random numbers. It is suitable for scenarios with high security requirements, such as generating user tokens, temporary IDs, etc.
Simple random generation (browser environment)
In the browser, you may not want to introduce additional libraries, and you can implement a basic version with pure JavaScript:
function generateUUID() {
return 'xxxxxxx-xxxx-4xxx-yxxxx-xxxxxxxxxxxxxxx'.replace(/[xy]/g, c => {
const r = Math.random() * 16 | 0;
const v = c === 'x' ? r : (r & 0x3) | 0x8;
return v.toString(16);
});
} This method is simple and easy to use and is suitable for scenarios that do not require high security, such as local debugging, temporary keys, etc. However, it should be noted that Math.random() is not random enough to be used for safe and sensitive purposes.
Use third-party libraries (such as uuid)
If you want more comprehensive features, or need to support different versions of UUID (such as UUIDv1, v4, v5), you can directly use popular libraries, such as uuid :
npm install uuid
Then use it like this:
import { v4 as uuidv4 } from 'uuid';
console.log(uuidv4()); // The output is similar: '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'This method is most recommended for production environments because it is well maintained and has strong compatibility, and it also avoids errors when writing logic by yourself.
Tips and notes
- UUID v4 is the most commonly used form at present, relying on random number generation.
- If you need a timestamp-based UUID (v1), you need to pay attention to the risk of exposing time information.
- In frameworks such as React or Vue, do not treat UUID as the only source of component keys unless uniqueness guarantees are indeed required.
- Multiple calls to generate functions do not guarantee that uniqueness is absolutely true, but in most cases it is "unique".
Basically that's it. The implementation method can be selected according to your operating environment and needs.
The above is the detailed content of How to create a GUID/UUID in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!
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