generating unique user and object ids

Question

I have two data objects, the user and a record.

The user should have a unique id, the record should have one too. The record has an owner, the user, each record contains the userId. So I created a simple Id generator

$( document ).ready(function() {
    $("#btn").click(function(){ 
      createId();
    });
});

var myIds = [];

function createId(){ // Create new ID and push it to the ID collection
  var id = generateNewId();
  myIds.push(id);
  console.log("The current id is: ");
  console.log(id);
  console.log("The array contains: ");
  console.log(myIds);
}

function generateNewId(){ // Check for existing IDs
  var newId = getNewId();
  if($.inArray(newId, myIds) > -1){ // Does it already exist?
    newId = generateNewId(); // 
  } 
  else{
    return newId;
  }
}

function getNewId(){ // ID generator
    var possibleChars = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    var serialLength = 20;
    var generatedId = '';

    for (var i = 0; i < serialLength; i++) {
      var randomNumber = Math.floor(Math.random() * possibleChars.length);
      generatedId += possibleChars.substring(randomNumber, randomNumber + 1);
    }

    return generatedId;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<button id="btn">Add new ID</button>

So this generator works fine for both ids. But what is the correct way in generating user ids?

Is there a way to generate a unique user id when creating an account in country ? at the time ? by user ?

The record object has an ID too, is there a way to make it contain parts of its owner, the user id?

The shown generator is able to create a large range of possible ids. But what happens, when there is no possibility anymore? That's why I want a "better" way of creating IDs.

Answer 1

If you're using node, you can use uuid: https://www.npmjs.com/package/uuid This package allows you to create universal unique IDs.

On browser side, your best bet is implement a simple function that gets the job done. Yours is not bad but you risk collision. I would use the one from npm uuidv4 which is more evolved:

function uuidv4() {
  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);
  });
}

const uuidv4es8 = () =>
  'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
    const r = Math.random() * 16 | 0
    return (c == 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  });

//EDIT customize it if you want:
const uuidv4es8WithoutDash = () => 
  'xxxxxxxxxxxx4xxxyxxxxxxxxxxxxxxx'.replace(/[xy]/g, c => {
    const r = Math.random() * 16 | 0
    return (c == 'x' ? r : (r & 0x3 | 0x8)).toString(16)
  });

const uuidFactory = 
  (myFormat,encodingBase) => 
   () =>
     myFormat.replace(/[a-zA-Z]/g, c => (Math.random() *  encodingBase| 0).toString(encodingBase))

console.log(uuidv4())
console.log(uuidv4())
console.log(uuidv4())
console.log(uuidv4())
console.log(uuidv4())

console.log(uuidv4es8())

//EDIT: delete the dash if you want !
console.log(uuidv4es8WithoutDash())

//Create a function that returns uuid as you want them:
let myUuidv4es8 = uuidFactory('1-xxxxx-xxxxx',23)
console.log(myUuidv4es8())
console.log(myUuidv4es8())

myUuidv4es8 = uuidFactory('x-xx-xxx-xxxxx',6)
console.log(myUuidv4es8())
console.log(myUuidv4es8())
//australian phone number:
myUuidv4es8 = uuidFactory('61-xxx-xxx-xxx',10)
console.log(myUuidv4es8())
console.log(myUuidv4es8())