uuid Examples You Can Edit and Run

import { v4 as uuidv4 } from 'uuid'

// Each call returns a new random UUID string
console.log('v4 #1:', uuidv4())
console.log('v4 #2:', uuidv4())
console.log('v4 #3:', uuidv4())

// Give every record its own id
const todos = ['Write docs', 'Ship release', 'Reply to issues'].map((title) => ({ id: uuidv4(), title }))
for (const t of todos) console.log(`todo "${t.title}" ->`, t.id)

// rng option: a function that returns 16 random bytes
const rng = () => crypto.getRandomValues(new Uint8Array(16))
console.log('with rng option:', uuidv4({ rng }))

// random option: fixed bytes always give the same UUID
const random = Uint8Array.of(
  0x10, 0x91, 0x56, 0xbe, 0xc4, 0xfb, 0xc1, 0xea,
  0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
)
console.log('with fixed random bytes:', uuidv4({ random }))
console.log('string length:', uuidv4().length)