Getting index of an array's element based on its properties

Question

I have a JavaScript array of objects like this:

var myArray = [{...}, {...}, {...}]; 

Each object has unique id among other properties:

{    id: 4,   property1: 'something',   property2: 'something' } 

How can I get an index of a particular object in that array, if I only know its id property? So if I know that myArray[x].id == 4, how can I find x?

Answer 1

var index = myArray.map(function(el) {   return el.id; }).indexOf(4); 

For IE below version 9, map need a patch, or just use a loop.

Answer 2

Or with ES6 syntax:

let index = myArray.map( el => el.id ).indexOf(4) 

or

let index = myArray.findIndex( el => el.id === 4 )