Remove item from array using foreach - JavaScript

Question

Is it possible to remove something from an array using foreach?

var array = [1,2,3,4,5,6,7,8];

array.forEach(function(data){
    if (data == 4) {
        // do something here
    }
});

console.log(array);

Why would you? Use `filter`!!! – Bergi Jun 04 '15 at 18:41 — Bergi, Jun 04 '15 at 18:41

score 3 · Answer 1 · answered Jun 04 '15 at 18:19

I would advise against using the forEach function. It affects the iterator and skips the next item. Better: use a reverse for loop and remove the item by index.

var array = [1,2,3,4,5,6,7,8];

for (var i = array.length - 1; i > -1; i--) {
    if (array[i] == 4) {
        array.splice(i, 1);
    }
}

Fiddle: https://jsfiddle.net/uu94y8Lx/

Rahul Tripathi · Answer 2 · 2015-06-04T18:22:05.750

2

Try like this:

array.forEach(function(data){
   if (data == 4){
      console.log('done')
      array.splice(data, 1);
   }
});

Also as commented by mario its not recommended to modify the array you're looping on, so you can do like this:

var array1 = [];
array.forEach(function(data){
    if(array.length === 4){
        array1.push(data);
    }
});

Also you can use the for loop like this:

var array = [1,2,3,4,5,6,7,8],i;

for (i = 0; i < array.length; ++i) {
    if (array[i] === 4) {
        array.splice(i--, 1);
    }
}

console.log(array);

edited Jun 04 '15 at 18:22

answered Jun 04 '15 at 18:11

Rahul Tripathi

168,305
31
280
331

1

This does not work. See fiddle: https://jsfiddle.net/txzabe48/ removing items during foreach affects the iterator. I recommend doing a reverse for loop and remove by index. – Mario Tacke Jun 04 '15 at 18:14
1

@MarioTacke:- Updated my answer! – Rahul Tripathi Jun 04 '15 at 18:20

score 2 · Accepted Answer · answered Jun 04 '15 at 18:12

I would not recommend this. The forEach function iterates over the array and when you remove the current or a previous item it will skip the next item in the array. That being said if you really want to remove an item despite the problems you will run into it is possible to remove an item with array.splice(data, 1).

Remove item from array using foreach - JavaScript

3 Answers3