How can I remove a specific item from an array?

Question

I have an array of numbers and I'm using the .push() method to add elements to it. Is there a simple way to remove a specific element from an array? I'm looking for the equivalent of something like:

array.remove(number);

I have to use core JavaScript. Frameworks are not allowed.

Answer 1

Find the index of the array element you want to remove using indexOf, and then remove that index with splice.

The splice() method changes the contents of an array by removing existing elements and/or adding new elements.

const array = [2, 5, 9];

console.log(array);

const index = array.indexOf(5);
if (index > -1) {
  array.splice(index, 1);
}

// array = [2, 9]
console.log(array); 

 Run code snippet

Expand snippet

The second parameter of splice is the number of elements to remove. Note that splice modifies the array in place and returns a new array containing the elements that have been removed.

---

For the reason of completeness, here are functions. The first function removes only a single occurrence (i.e. removing the first match of 5 from [2,5,9,1,5,8,5]), while the second function removes all occurrences:

function removeItemOnce(arr, value) {
  var index = arr.indexOf(value);
  if (index > -1) {
    arr.splice(index, 1);
  }
  return arr;
}

function removeItemAll(arr, value) {
  var i = 0;
  while (i < arr.length) {
    if (arr[i] === value) {
      arr.splice(i, 1);
    } else {
      ++i;
    }
  }
  return arr;
}
//Usage
console.log(removeItemOnce([2,5,9,1,5,8,5], 5))
console.log(removeItemAll([2,5,9,1,5,8,5], 5))

Answer 2

A friend was having issues in Internet Explorer 8 and showed me what he did. I told him it was wrong, and he told me he got the answer here. The current top answer will not work in all browsers (Internet Explorer 8 for example), and it will only remove the first occurrence of the item.

Remove ALL instances from an array

function array_remove_index_by_value(arr, item)
{
 for (var i = arr.length; i--;)
 {
  if (arr[i] === item) {arr.splice(i, 1);}
 }
}

It loops through the array backwards (since indices and length will change as items are removed) and removes the item if it's found. It works in all browsers.