Creating Unique Strings (UUIDs) in JavaScript

Table of contents

The purpose
1. Example
Implementation
1. Implementation Examples
Reference

The purpose

Creating Unique Strings (UUIDs) in JavaScript.

Example

I’ll give the class a unique string (UUID) to use for instance verification instead of pointers.

Implementation

Here’s the translation:

You can create a unique string (UUID) with the following single line of code (it returns a different string with each call):

const uuid = self.crypto.randomUUID();

The returned value will be in the format of 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' (e.g., 'd6436922-c138-4ef3-bab6-5de2546f847e').

I read the documentation, but I couldn’t understand how uniqueness is maintained.

Although the probability is low, it’s not guaranteed that the same value won’t be generated.

If necessary, please implement a process to check if the generated UUID conflicts with any already issued UUIDs.

Implementation Examples

For examples where a class needs a unique string (UUID) to identify instances instead of using pointers, the following implementation should be sufficient.

class tool {
    #uid;
    constructor(){
        this.#uid = self.crypto.randomUUID();
    }
    get uid(){return this.#uid}
}

Reference

Crypto: randomUUID() メソッド - Web API | MDN

randomUUID() は Crypto インターフェイスのメソッドで、暗号強度の強い乱数生成器を用いて v4 UUID を生成するのに用いられます。