Factorising a function by using a forEach-loop

Question

I would like to write a shorter code for find by using .forEach but I found problems with the counting and return does not work:

function find(array, element) {
 array.forEach((_, i) => {
  if (array[i] === element) {
    return i;
  }
 })
 return "Not found";  
}

let array = [2,3,5,7,11];


function find(array, element) {
  for (let i = 0; i < array.length; i++) {
    console.log(i)
    if (array[i] === element) {
      return i;
    }
  }
  return "Not found";
}

console.log(find(array, 5)) //2
console.log(find(array, 12)) //Not found

You are returning to the caller of the callback function, and not your actual `find()` function call. Returning from `.forEach()` doesn't do much except for terminating that particular iteration that you're on. — Nick Parsons, Oct 05 '21 at 08:09
Just making sure you are aware that [Array.prototype.find()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find) exists? — Jesper, Oct 05 '21 at 08:10
@Jesper more like [Array.prototype.indexOf()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexof) as the goal here is to get the index of the element — Krzysztof Krzeszewski, Oct 05 '21 at 08:11
Here's a fixed version: https://jsfiddle.net/qt1Lvdsk/ (also, did you mean "refactoring"?) — , Oct 05 '21 at 08:19
Write better code, not "shorter" code. `forEach` is the wrong tool here. — Bergi, Oct 05 '21 at 09:16

score 1 · Answer 1 · answered Oct 05 '21 at 09:05

1

let array = [2,3,5,7,11];

function find(array, element) {

let index =  array.indexOf(element) != -1 ? array.indexOf(element) : "Not Found";  

return index;

}

console.log(find(array, 5))

console.log(find(array, 12))

answered Oct 05 '21 at 09:05

Ravi Kumar

11
1

Erfan Geramian · Answer 2 · 2021-10-05T09:34:54.233

1

return is not going to work inside a forEach I suggest you use the filter function instead. but if you insist on using forEach you can use this code as a sample.

function find(array, element) {
let result="not found";
 array.forEach((arrayItem, i) => {
  if (arrayItem === element) {
    result = i;
  }
 })
 return result;  
}

edited Oct 05 '21 at 09:34

answered Oct 05 '21 at 09:11

Erfan Geramian

187
8

1

It would be a good idea to declare `let result = 'Not found';` in case the entry number is not in the array. So it would return `Not found` instead of `undefined` – Gass Oct 05 '21 at 09:33

Factorising a function by using a forEach-loop

2 Answers2