get index of array item code example

Example 1: how to find the index of a value in an array in javascript

var list = ["apple","banana","orange"]

var index_of_apple = list.indexOf("apple") // 0

Example 2: js find index in list

let myList = ['foo', 'bar', 'qux'];

myList.indexOf('bar');	// 1

Example 3: make indexOF in js

function indexOf(arr, value) {
  for (let [i, e] of arr.entries()) {
    if (value == e) return i;
  }
  return -1;
}
indexOf([1,2,3], 2);                     //returns 1