Generate unique id with javascript not exceeding an integer

Question

I would like to generate a unique id with javascript without exceeding an integer type.

With the following solution: (new Date()).getTime() but out of the range of an integer.

Thanks for your suggestion.

(pretty much any expression) | 0 will return a value from 0 to 2^32-1. (expr) >>> 1 will half that range. — Aki Suihkonen
– Aki Suihkonen, Commented Apr 23, 2013 at 18:44
My range for int is: -2147483648 until 2147483647. If possible I prefer using negative values so from -2147483648 to 0. — Bronzato
– Bronzato, Commented Apr 23, 2013 at 18:47
Have you read the other answers on that linked post? A running index is very simple, and you can define its range very easily. — Bergi
– Bergi, Commented Apr 23, 2013 at 18:50
@Salman: you are right. I mean an integer in a more general sense. To be more precise I use c-sharp integers. — Bronzato
– Bronzato, Commented Apr 23, 2013 at 19:00

Lee Meador · Accepted Answer · 2013-04-23 18:47:12Z

4

Depends on what size integer you want. Here is a fiddle that shows a couple of ways to do it: http://jsfiddle.net/leemeador/C6YGa/

The idea is to do something like this for a 32 bit integer:

var i = new Date().getTime();
i = i & 0xffffffff;

answered Apr 23, 2013 at 18:47

Lee Meador

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2 Comments

Your solution is very interesting. One question: by using this 0xffff what is the range? Thanks.

Each 'F' is 4 bits. FFFF is 16 bits. FFFFFFFF is 32 bits.

Bartosh Lenart · Accepted Answer · 2017-02-01 16:07:47Z

0

Another way to generate unique key (id) with new ES6 Syntax, by returning a Number representing the milliseconds elapsed since the UNIX epoch:

export const generateRandomKey = () => Date.now();

You can write it in separate file and export. than import to your file using es6 syntax.

import {generateRandomKey} from './the/file/path.js';

answered Feb 1, 2017 at 16:07

Bartosh Lenart

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