how to generate uuid in node js code example

Example 1: uuid v4 react

npm install uuid
import { v4 as uuidv4 } from 'uuid';

Example 2: javascript generate uuid

function uuid(){
    var dt = new Date().getTime();
    var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
        var r = (dt + Math.random()*16)%16 | 0;
        dt = Math.floor(dt/16);
        return (c=='x' ? r :(r&0x3|0x8)).toString(16);
    });
    return uuid;
}

Example 3: javascript uniqie id

function uuid() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

var userID=uuid();//something like: "ec0c22fa-f909-48da-92cb-db17ecdb91c5"

Example 4: uuid javascript

uuidv4() {
    return 'xxxxxxxxxxxxxxxxxxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
      var r = (Math.random() * 16) | 0,
        v = c == 'x' ? r : (r & 0x3) | 0x8;
      return v.toString(16);
    });
  }