How to generate short uid like “aX4j9Z” (in JS)

Question

For my web application (in JavaScript) I want to generate short guids (for different objects - that are actually different types - strings and arrays of strings)

I w

Answer 1

Update 08/2020:

shortid has been deprecated in favor of nanoid which is smaller and faster:

• Small. 108 bytes (minified and gzipped). No dependencies. Size Limit controls the size.
• Fast. It is 40% faster than UUID.
• Safe. It uses cryptographically strong random APIs. Can be used in clusters.
• Compact. It uses a larger alphabet than UUID (A-Za-z0-9_-). So ID size was reduced from 36 to 21 symbols.
• Portable. Nano ID was ported to 14 programming languages.

import { nanoid } from 'nanoid'

// 21 characters (default)
// ~149 billion years needed, in order to have a 1% probability of at least one collision.
console.log(nanoid()) //=> "V1StGXR8_Z5jdHi6B-myT"

// 11 characters
// ~139 years needed, in order to have a 1% probability of at least one collision.
console.log(nanoid(11)) //=> "bdkjNOkq9PO"

More info here : https://zelark.github.io/nano-id-cc/

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Old answer

There is also an awesome npm package for this : shortid

Amazingly short non-sequential url-friendly unique id generator.

ShortId creates amazingly short non-sequential url-friendly unique ids. Perfect for url shorteners, MongoDB and Redis ids, and any other id users might see.

• By default 7-14 url-friendly characters: A-Z, a-z, 0-9, _-
• Non-sequential so they are not predictable.
• Supports cluster (automatically), custom seeds, custom alphabet.
• Can generate any number of ids without duplicates, even millions per day.
• Perfect for games, especially if you are concerned about cheating so you don't want an easily guessable id.
• Apps can be restarted any number of times without any chance of repeating an id.
• Popular replacement for Mongo ID/Mongoose ID.
• Works in Node, io.js, and web browsers.
• Includes Mocha tests.

Usage

var shortid = require('shortid');
console.log(shortid.generate()); //PPBqWA9