How can I remove a specific item from an array?

How do I remove a specific value from an array? Something like:

array.remove(value);  // removes all elements with value

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

array.remove(index) or array.pull(index) would make a lot of sense. splice is very useful, but a remove() or pull() method would be welcome... Search the internet, you will find a lot of "What is the opposite of push() in JavaScript?" questions. Would be great if the answare could be as simples as plain english: Pull!
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);
array.filter((_, index) => index != number);
@Gustavo Gonçalves I do not understand the problem: the opposite of Array#push() is well-known. (Of course, that is not what this question is asking for.)

3
32 revs, 27 users 13%

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) { // only splice array when item is found array.splice(index, 1); // 2nd parameter means remove one item only } // array = [2, 9] console.log(array);

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))

In TypeScript, these functions can stay type-safe with a type parameter:

function removeItem<T>(arr: Array<T>, value: T): Array<T> { 
  const index = arr.indexOf(value);
  if (index > -1) {
    arr.splice(index, 1);
  }
  return arr;
}

Serious question: why doesn't JavaScript allow the simple and intuitive method of removing an element at an index? A simple, elegant, myArray.remove(index); seems to be the best solution and is implemented in many other languages (a lot of them older than JavaScript.)
@Andrew sets and arrays are two completely different collection types.
You can simplify this solution by counting down instead of up: for ( var i = ary.length - 1; i >= 0; i-- ) { if ( ary[i] === value ) { ary.remove(i)} }
function remove(item,array) { var new_array = [] new_ array = array.filter((ar)=> ar != item) return new_array }
I'm a bit late to the party, but here's my two cents: @a2br: Array.unshift() is basically what pull() would be if it existed! @Bob: Personally, I think it's good that nothing similar to Array.remove() exists. We don't want JavaScript to end up like PHP, now do we? xD
t
tagurit

Edited on 2016 October

Do it simple, intuitive and explicit (Occam's razor)

Do it immutable (original array stays unchanged)

Do it with standard JavaScript functions, if your browser doesn't support them - use polyfill

In this code example I use array.filter(...) function to remove unwanted items from an array. This function doesn't change the original array and creates a new one. If your browser doesn't support this function (e.g. Internet Explorer before version 9, or Firefox before version 1.5), consider polyfilling with core-js.

Removing item (ECMA-262 Edition 5 code AKA old style JavaScript)

var value = 3

var arr = [1, 2, 3, 4, 5, 3]

arr = arr.filter(function(item) {
    return item !== value
})

console.log(arr)
// [ 1, 2, 4, 5 ]

Removing item (ECMAScript 6 code)

let value = 3

let arr = [1, 2, 3, 4, 5, 3]

arr = arr.filter(item => item !== value)

console.log(arr)
// [ 1, 2, 4, 5 ]

IMPORTANT ECMAScript 6 () => {} arrow function syntax is not supported in Internet Explorer at all, Chrome before version 45, Firefox before version 22, and Safari before version 10. To use ECMAScript 6 syntax in old browsers you can use BabelJS.

Removing multiple items (ECMAScript 7 code)

An additional advantage of this method is that you can remove multiple items

let forDeletion = [2, 3, 5]

let arr = [1, 2, 3, 4, 5, 3]

arr = arr.filter(item => !forDeletion.includes(item))
// !!! Read below about array.includes(...) support !!!

console.log(arr)
// [ 1, 4 ]

IMPORTANT array.includes(...) function is not supported in Internet Explorer at all, Chrome before version 47, Firefox before version 43, Safari before version 9, and Edge before version 14 but you can polyfill with core-js.

Removing multiple items (in the future, maybe)

If the "This-Binding Syntax" proposal is ever accepted, you'll be able to do this:

// array-lib.js

export function remove(...forDeletion) {
    return this.filter(item => !forDeletion.includes(item))
}

// main.js

import { remove } from './array-lib.js'

let arr = [1, 2, 3, 4, 5, 3]

// :: This-Binding Syntax Proposal
// using "remove" function as "virtual method"
// without extending Array.prototype
arr = arr::remove(2, 3, 5)

console.log(arr)
// [ 1, 4 ]

Try it yourself in BabelJS :)

Reference

Array.prototype.includes

Functional composition


what if content of array are objects and nested objects
doesn't filter return an empty array if the condition isn't met? So you have to be sure the element is going to be there or you're getting it empty on return.
The above answer would work only for primitive data types though for JavaScript as the object equality is not strict
Doesn't work if I want to remove only one 3 from the array
L
Lioness100

I don't know how you are expecting array.remove(int) to behave. There are three possibilities I can think of that you might want.

To remove an element of an array at an index i:

array.splice(i, 1);

If you want to remove every element with value number from the array:

for (var i = array.length - 1; i >= 0; i--) {
 if (array[i] === number) {
  array.splice(i, 1);
 }
}

If you just want to make the element at index i no longer exist, but you don't want the indexes of the other elements to change:

delete array[i];

Great options to do the remove task.
delete array[i] would degrade the performance of the application and is considered a bad pratice
A
Andrew

It depends on whether you want to keep an empty spot or not.

If you do want an empty slot:

array[index] = undefined;

If you don't want an empty slot:

//To keep the original:
//oldArray = [...array];

//This modifies the array.
array.splice(index, 1);

And if you need the value of that item, you can just store the returned array's element:

var value = array.splice(index, 1)[0];

If you want to remove at either end of the array, you can use array.pop() for the last one or array.shift() for the first one (both return the value of the item as well).

If you don't know the index of the item, you can use array.indexOf(item) to get it (in a if() to get one item or in a while() to get all of them). array.indexOf(item) returns either the index or -1 if not found. 


It's kinda funny that splice returns another array built out of the removed elements. I wrote something which assumed splice would return the newly modified list (like what immutable collections would do, for example). So, in this particular case of only one item in the list, and that item being removed, the returned list is exactly identical to the original one after splicing that one item. So, my app went into an infinite loop.
B
Ben Lesh

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 removeAllInstances(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.


S
Saša

There are two major approaches

splice(): anArray.splice(index, 1); let fruits = ['Apple', 'Banana', 'Mango', 'Orange'] let removed = fruits.splice(2, 1); // fruits is ['Apple', 'Banana', 'Orange'] // removed is ['Mango'] delete: delete anArray[index]; let fruits = ['Apple', 'Banana', 'Mango', 'Orange'] let removed = delete fruits(2); // fruits is ['Apple', 'Banana', undefined, 'Orange'] // removed is true

Be careful when you use the delete for an array. It is good for deleting attributes of objects, but not so good for arrays. It is better to use splice for arrays.

Keep in mind that when you use delete for an array you could get wrong results for anArray.length. In other words, delete would remove the element, but it wouldn't update the value of the length property.

You can also expect to have holes in index numbers after using delete, e.g. you could end up with having indexes 1, 3, 4, 8, 9, and 11 and length as it was before using delete. In that case, all indexed for loops would crash, since indexes are no longer sequential.

If you are forced to use delete for some reason, then you should use for each loops when you need to loop through arrays. As the matter of fact, always avoid using indexed for loops, if possible. That way the code would be more robust and less prone to problems with indexes.


f
flosommerfeld

Array.prototype.removeByValue = function (val) { for (var i = 0; i < this.length; i++) { if (this[i] === val) { this.splice(i, 1); i--; } } return this; } var fruits = ['apple', 'banana', 'carrot', 'orange']; fruits.removeByValue('banana'); console.log(fruits); // -> ['apple', 'carrot', 'orange']


s
slosd

There is no need to use indexOf or splice. However, it performs better if you only want to remove one occurrence of an element.

Find and move (move):

function move(arr, val) {
  var j = 0;
  for (var i = 0, l = arr.length; i < l; i++) {
    if (arr[i] !== val) {
      arr[j++] = arr[i];
    }
  }
  arr.length = j;
}

Use indexOf and splice (indexof):

function indexof(arr, val) {
  var i;
  while ((i = arr.indexOf(val)) != -1) {
    arr.splice(i, 1);
  }
}

Use only splice (splice):

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

Run-times on nodejs for array with 1000 elements (average over 10000 runs):

indexof is approximately 10x slower than move. Even if improved by removing the call to indexOf in splice it performs much worse than move.

Remove all occurrences:
    move 0.0048 ms
    indexof 0.0463 ms
    splice 0.0359 ms

Remove first occurrence:
    move_one 0.0041 ms
    indexof_one 0.0021 ms

a
amd

This provides a predicate instead of a value.

NOTE: it will update the given array, and return the affected rows.

Usage

var removed = helper.remove(arr, row => row.id === 5 );

var removed = helper.removeAll(arr, row => row.name.startsWith('BMW'));

Definition

var helper = {
 // Remove and return the first occurrence

 remove: function(array, predicate) {
  for (var i = 0; i < array.length; i++) {
   if (predicate(array[i])) {
    return array.splice(i, 1);
   }
  }
 },

 // Remove and return all occurrences

 removeAll: function(array, predicate) {
  var removed = [];

  for (var i = 0; i < array.length; ) {
   if (predicate(array[i])) {
    removed.push(array.splice(i, 1));
    continue;
   }
   i++;
  }
  return removed;
 },
};

put your code in code snippet so other users could see the result
M
Masoud Aghaei

You can do it easily with the filter method:

function remove(arrOriginal, elementToRemove){ return arrOriginal.filter(function(el){return el !== elementToRemove}); } console.log(remove([1, 2, 1, 0, 3, 1, 4], 1));

This removes all elements from the array and also works faster than a combination of slice and indexOf.


m
magiccrafter

John Resig posted a good implementation:

// Array Remove - By John Resig (MIT Licensed)
Array.prototype.remove = function(from, to) {
  var rest = this.slice((to || from) + 1 || this.length);
  this.length = from < 0 ? this.length + from : from;
  return this.push.apply(this, rest);
};

If you don’t want to extend a global object, you can do something like the following, instead:

// Array Remove - By John Resig (MIT Licensed)
Array.remove = function(array, from, to) {
    var rest = array.slice((to || from) + 1 || array.length);
    array.length = from < 0 ? array.length + from : from;
    return array.push.apply(array, rest);
};

But the main reason I am posting this is to warn users against the alternative implementation suggested in the comments on that page (Dec 14, 2007):

Array.prototype.remove = function(from, to){
  this.splice(from, (to=[0,from||1,++to-from][arguments.length])<0?this.length+to:to);
  return this.length;
};

It seems to work well at first, but through a painful process I discovered it fails when trying to remove the second to last element in an array. For example, if you have a 10-element array and you try to remove the 9th element with this:

myArray.remove(8);

You end up with an 8-element array. Don't know why but I confirmed John's original implementation doesn't have this problem.


d
darmis

You can use ES6. For example to delete the value '3' in this case:

var array=['1','2','3','4','5','6']
var newArray = array.filter((value)=>value!='3');
console.log(newArray);

Output :

["1", "2", "4", "5", "6"]

This answer is nice because it creates a copy of the original array, instead of modifying the original directly.
Note: Array.prototype.filter is ECMAScript 5.1 (No IE8). for more specific solutions: stackoverflow.com/a/54390552/8958729
P
Peter Mortensen

Underscore.js can be used to solve issues with multiple browsers. It uses in-build browser methods if present. If they are absent like in the case of older Internet Explorer versions it uses its own custom methods.

A simple example to remove elements from array (from the website):

_.without([1, 2, 1, 0, 3, 1, 4], 0, 1); // => [2, 3, 4]

though elegant and concise, OP clearly mentioned core JS only
P
Peter Mortensen

If you want a new array with the deleted positions removed, you can always delete the specific element and filter out the array. It might need an extension of the array object for browsers that don't implement the filter method, but in the long term it's easier since all you do is this:

var my_array = [1, 2, 3, 4, 5, 6];
delete my_array[4];
console.log(my_array.filter(function(a){return typeof a !== 'undefined';}));

It should display [1, 2, 3, 4, 6].


B
Bhargav Rao

Here are a few ways to remove an item from an array using JavaScript.

All the method described do not mutate the original array, and instead create a new one.

If you know the index of an item

Suppose you have an array, and you want to remove an item in position i.

One method is to use slice():

const items = ['a', 'b', 'c', 'd', 'e', 'f'] const i = 3 const filteredItems = items.slice(0, i).concat(items.slice(i+1, items.length)) console.log(filteredItems)

slice() creates a new array with the indexes it receives. We simply create a new array, from start to the index we want to remove, and concatenate another array from the first position following the one we removed to the end of the array.

If you know the value

In this case, one good option is to use filter(), which offers a more declarative approach:

const items = ['a', 'b', 'c', 'd', 'e', 'f'] const valueToRemove = 'c' const filteredItems = items.filter(item => item !== valueToRemove) console.log(filteredItems)

This uses the ES6 arrow functions. You can use the traditional functions to support older browsers:

const items = ['a', 'b', 'c', 'd', 'e', 'f'] const valueToRemove = 'c' const filteredItems = items.filter(function(item) { return item !== valueToRemove }) console.log(filteredItems)

or you can use Babel and transpile the ES6 code back to ES5 to make it more digestible to old browsers, yet write modern JavaScript in your code.

Removing multiple items

What if instead of a single item, you want to remove many items?

Let's find the simplest solution.

By index

You can just create a function and remove items in series:

const items = ['a', 'b', 'c', 'd', 'e', 'f'] const removeItem = (items, i) => items.slice(0, i-1).concat(items.slice(i, items.length)) let filteredItems = removeItem(items, 3) filteredItems = removeItem(filteredItems, 5) //["a", "b", "c", "d"] console.log(filteredItems)

By value

You can search for inclusion inside the callback function:

const items = ['a', 'b', 'c', 'd', 'e', 'f'] const valuesToRemove = ['c', 'd'] const filteredItems = items.filter(item => !valuesToRemove.includes(item)) // ["a", "b", "e", "f"] console.log(filteredItems)

Avoid mutating the original array

splice() (not to be confused with slice()) mutates the original array, and should be avoided.

(originally posted on my site https://flaviocopes.com/how-to-remove-item-from-array/)


Can you elaborate on why modifing the original array should be avoided? I'm iterating over an array in reverse order and want to either delete or keep the current element. After the loop I have only the kept elements left inside the array and can use it directly for the next operation. Your example would have me duplicate the array on every iteration. I could also create a new array and push all elements to keep into it, but wouldn't that be quite the memory overhead compared to my original approach?
M
Masoud Aghaei

Check out this code. It works in every major browser.

remove_item = function(arr, value) { var b = ''; for (b in arr) { if (arr[b] === value) { arr.splice(b, 1); break; } } return arr; }; var array = [1,3,5,6,5,9,5,3,55] var res = remove_item(array,5); console.log(res)


@RolandIllig Except the use of a for in-loop and the fact that the script could stopped earlier, by returning the result from the loop directly. The upvotes are reasonable ;)
I should also reiterate yckart's comment that for( i = 0; i < arr.length; i++ ) would be a better approach since it preserves the exact indices versus whatever order the browser decides to store the items (with for in). Doing so also lets you get the array index of a value if you need it.
C
Chun Yang

You can use lodash _.pull (mutate array), _.pullAt (mutate array) or _.without (does't mutate array),

var array1 = ['a', 'b', 'c', 'd']
_.pull(array1, 'c')
console.log(array1) // ['a', 'b', 'd']

var array2 = ['e', 'f', 'g', 'h']
_.pullAt(array2, 0)
console.log(array2) // ['f', 'g', 'h']

var array3 = ['i', 'j', 'k', 'l']
var newArray = _.without(array3, 'i') // ['j', 'k', 'l']
console.log(array3) // ['i', 'j', 'k', 'l']

That's not core JS as the OP requested, is it?
@some-non-descript-user You are right. But a lot of users like me come here looking for a general answer not just for the OP only.
M
Max Alexander Hanna

Removing a particular element/string from an array can be done in a one-liner:

theArray.splice(theArray.indexOf("stringToRemoveFromArray"), 1);

where:

theArray: the array you want to remove something particular from

stringToRemoveFromArray: the string you want to be removed and 1 is the number of elements you want to remove.

NOTE: If "stringToRemoveFromArray" is not located in the array, this will remove the last element of the array.

It's always good practice to check if the element exists in your array first, before removing it.

if (theArray.indexOf("stringToRemoveFromArray") >= 0){
   theArray.splice(theArray.indexOf("stringToRemoveFromArray"), 1);
}

Depending if you have newer or older version of Ecmascript running on your client's computers:

var array=['1','2','3','4','5','6']
var newArray = array.filter((value)=>value!='3');

OR

var array = ['1','2','3','4','5','6'];
var newArray = array.filter(function(item){ return item !== '3' });

Where '3' is the value you want to be removed from the array. The array would then become : ['1','2','4','5','6']


This is the answer that worked for me when trying to update an array based on radio button toggling.
Beware, if "stringToRemoveFromArray" is not located your in array, this will remove last element of array.
R
Ran Turner

Using filter is an elegant way to achieve this requirement

const num = 3; let arr = [1, 2, 3, 4]; arr = arr.filter(x => x !== num); console.log(arr); // [1, 2, 4]

By the way, filter will remove all of the occurrences matched in the condition (not just the first occurrence) like you can see in the following example

const num = 3; let arr = [1, 2, 3, 3, 3, 4]; arr = arr.filter(x => x !== num); console.log(arr); // [1, 2, 4]

In case, you just want to remove the first occurence, you can use the Array.prototype.splice() method

const num = 3; let arr = [1, 2, 3, 3, 3, 4]; arr.splice(arr.indexOf(num), 1); console.log(arr); // [1, 2, 3, 3, 4]


d
dipenparmar12

ES6 & without mutation: (October 2016)

const removeByIndex = (list, index) => [ ...list.slice(0, index), ...list.slice(index + 1) ]; output = removeByIndex([33,22,11,44],1) //=> [33,11,44] console.log(output)


Why not just use filter then? array.filter((_, index) => index !== removedIndex);.
P
Peter Mortensen

ES10

This post summarizes common approaches to element removal from an array as of ECMAScript 2019 (ES10).

1. General cases

1.1. Removing Array element by value using .splice()

| In-place: Yes | | Removes duplicates: Yes(loop), No(indexOf) | | By value / index: By index |

If you know the value you want to remove from an array you can use the splice method. First, you must identify the index of the target item. You then use the index as the start element and remove just one element.

// With a 'for' loop
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
for( let i = 0; i < arr.length; i++){
  if ( arr[i] === 5) {
    arr.splice(i, 1);
  }
} // => [1, 2, 3, 4, 6, 7, 8, 9, 0]

// With the .indexOf() method
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
const i = arr.indexOf(5);
arr.splice(i, 1); // => [1, 2, 3, 4, 6, 7, 8, 9, 0]

1.2. Removing Array element using the .filter() method

| In-place: No | | Removes duplicates: Yes | | By value / index: By value |

The specific element can be filtered out from the array, by providing a filtering function. Such function is then called for every element in the array.

const value = 3
let arr = [1, 2, 3, 4, 5, 3]
arr = arr.filter(item => item !== value)
console.log(arr)
// [ 1, 2, 4, 5 ]

1.3. Removing Array element by extending Array.prototype

| In-place: Yes/No (Depends on implementation) | | Removes duplicates: Yes/No (Depends on implementation) | | By value / index: By index / By value (Depends on implementation) |

The prototype of Array can be extended with additional methods. Such methods will be then available to use on created arrays.

Note: Extending prototypes of objects from the standard library of JavaScript (like Array) is considered by some as an antipattern.

// In-place, removes all, by value implementation
Array.prototype.remove = function(item) {
    for (let i = 0; i < this.length; i++) {
        if (this[i] === item) {
            this.splice(i, 1);
        }
    }
}
const arr1 = [1,2,3,1];
arr1.remove(1) // arr1 equals [2,3]

// Non-stationary, removes first, by value implementation
Array.prototype.remove = function(item) {
    const arr = this.slice();
    for (let i = 0; i < this.length; i++) {
        if (arr[i] === item) {
            arr.splice(i, 1);
            return arr;
        }
    }
    return arr;
}
let arr2 = [1,2,3,1];
arr2 = arr2.remove(1) // arr2 equals [2,3,1]

1.4. Removing Array element using the delete operator

| In-place: Yes | | Removes duplicates: No | | By value / index: By index |

Using the delete operator does not affect the length property. Nor does it affect the indexes of subsequent elements. The array becomes sparse, which is a fancy way of saying the deleted item is not removed but becomes undefined.

const arr = [1, 2, 3, 4, 5, 6];
delete arr[4]; // Delete element with index 4
console.log( arr ); // [1, 2, 3, 4, undefined, 6]

The delete operator is designed to remove properties from JavaScript objects, which arrays are objects.

1.5. Removing Array element using Object utilities (>= ES10)

| In-place: No | | Removes duplicates: Yes | | By value / index: By value |

ES10 introduced Object.fromEntries, which can be used to create the desired Array from any Array-like object and filter unwanted elements during the process.

const object = [1,2,3,4];
const valueToRemove = 3;
const arr = Object.values(Object.fromEntries(
  Object.entries(object)
  .filter(([ key, val ]) => val !== valueToRemove)
));
console.log(arr); // [1,2,4]

2. Special cases

2.1 Removing element if it's at the end of the Array

2.1.1. Changing Array length

| In-place: Yes | | Removes duplicates: No | | By value / index: N/A |

JavaScript Array elements can be removed from the end of an array by setting the length property to a value less than the current value. Any element whose index is greater than or equal to the new length will be removed.

const arr = [1, 2, 3, 4, 5, 6];
arr.length = 5; // Set length to remove element
console.log( arr ); // [1, 2, 3, 4, 5]

2.1.2. Using .pop() method

| In-place: Yes | | Removes duplicates: No | | By value / index: N/A |

The pop method removes the last element of the array, returns that element, and updates the length property. The pop method modifies the array on which it is invoked, This means unlike using delete the last element is removed completely and the array length reduced.

const arr = [1, 2, 3, 4, 5, 6];
arr.pop(); // returns 6
console.log( arr ); // [1, 2, 3, 4, 5]

2.2. Removing element if it's at the beginning of the Array

| In-place: Yes | | Removes duplicates: No | | By value / index: N/A |

The .shift() method works much like the pop method except it removes the first element of a JavaScript array instead of the last. When the element is removed the remaining elements are shifted down.

const arr = [1, 2, 3, 4];
arr.shift(); // returns 1
console.log( arr ); // [2, 3, 4]

2.3. Removing element if it's the only element in the Array

| In-place: Yes | | Removes duplicates: N/A | | By value / index: N/A |

The fastest technique is to set an array variable to an empty array.

let arr = [1];
arr = []; //empty array

Alternatively technique from 2.1.1 can be used by setting length to 0.


A
Ammar

Performance

Today (2019-12-09) I conduct performance tests on macOS v10.13.6 (High Sierra) for chosen solutions. I show delete (A), but I do not use it in comparison with other methods, because it left empty space in the array.

The conclusions

the fastest solution is array.splice (C) (except Safari for small arrays where it has the second time)

for big arrays, array.slice+splice (H) is the fastest immutable solution for Firefox and Safari; Array.from (B) is fastest in Chrome

mutable solutions are usually 1.5x-6x faster than immutable

for small tables on Safari, surprisingly the mutable solution (C) is slower than the immutable solution (G)

Details

In tests, I remove the middle element from the array in different ways. The A, C solutions are in-place. The B, D, E, F, G, H solutions are immutable.

Results for an array with 10 elements

https://i.stack.imgur.com/foNhq.png

In Chrome the array.splice (C) is the fastest in-place solution. The array.filter (D) is the fastest immutable solution. The slowest is array.slice (F). You can perform the test on your machine here.

Results for an array with 1.000.000 elements

https://i.stack.imgur.com/7zCJt.png

In Chrome the array.splice (C) is the fastest in-place solution (the delete (C) is similar fast - but it left an empty slot in the array (so it does not perform a 'full remove')). The array.slice-splice (H) is the fastest immutable solution. The slowest is array.filter (D and E). You can perform the test on your machine here.

var a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]; var log = (letter,array) => console.log(letter, array.join `,`); function A(array) { var index = array.indexOf(5); delete array[index]; log('A', array); } function B(array) { var index = array.indexOf(5); var arr = Array.from(array); arr.splice(index, 1) log('B', arr); } function C(array) { var index = array.indexOf(5); array.splice(index, 1); log('C', array); } function D(array) { var arr = array.filter(item => item !== 5) log('D', arr); } function E(array) { var index = array.indexOf(5); var arr = array.filter((item, i) => i !== index) log('E', arr); } function F(array) { var index = array.indexOf(5); var arr = array.slice(0, index).concat(array.slice(index + 1)) log('F', arr); } function G(array) { var index = array.indexOf(5); var arr = [...array.slice(0, index), ...array.slice(index + 1)] log('G', arr); } function H(array) { var index = array.indexOf(5); var arr = array.slice(0); arr.splice(index, 1); log('H', arr); } A([...a]); B([...a]); C([...a]); D([...a]); E([...a]); F([...a]); G([...a]); H([...a]); This snippet only presents code used in performance tests - it does not perform tests itself.

Comparison for browsers: Chrome v78.0.0, Safari v13.0.4, and Firefox v71.0.0

https://i.stack.imgur.com/Ct9DN.png


P
Peter Mortensen

OK, for example you have the array below:

var num = [1, 2, 3, 4, 5];

And we want to delete number 4. You can simply use the below code:

num.splice(num.indexOf(4), 1); // num will be [1, 2, 3, 5];

If you are reusing this function, you write a reusable function which will be attached to the native array function like below:

Array.prototype.remove = Array.prototype.remove || function(x) {
  const i = this.indexOf(x);
  if(i===-1)
      return;
  this.splice(i, 1); // num.remove(5) === [1, 2, 3];
}

But how about if you have the below array instead with a few [5]s in the array?

var num = [5, 6, 5, 4, 5, 1, 5];

We need a loop to check them all, but an easier and more efficient way is using built-in JavaScript functions, so we write a function which use a filter like below instead:

const _removeValue = (arr, x) => arr.filter(n => n!==x);
//_removeValue([1, 2, 3, 4, 5, 5, 6, 5], 5) // Return [1, 2, 3, 4, 6]

Also there are third-party libraries which do help you to do this, like Lodash or Underscore. For more information, look at lodash _.pull, _.pullAt or _.without.


y
yckart

I'm pretty new to JavaScript and needed this functionality. I merely wrote this:

function removeFromArray(array, item, index) {
  while((index = array.indexOf(item)) > -1) {
    array.splice(index, 1);
  }
}

Then when I want to use it:

//Set-up some dummy data
var dummyObj = {name:"meow"};
var dummyArray = [dummyObj, "item1", "item1", "item2"];

//Remove the dummy data
removeFromArray(dummyArray, dummyObj);
removeFromArray(dummyArray, "item2");

Output - As expected. ["item1", "item1"]

You may have different needs than I, so you can easily modify it to suit them. I hope this helps someone.


This is going to have terrible behavior if your array is really long and there are several instances of the element in it. The indexOf method of array will start at the beginning every time, so your cost is going to be O(n^2).
@Zag: It has a name: Shlemiel the Painter's Algorithm
t
tagurit

I want to answer based on ECMAScript 6. Assume you have an array like below:

let arr = [1,2,3,4];

If you want to delete at a special index like 2, write the below code:

arr.splice(2, 1); //=> arr became [1,2,4]

But if you want to delete a special item like 3 and you don't know its index, do like below:

arr = arr.filter(e => e !== 3); //=> arr became [1,2,4]

Hint: please use an arrow function for filter callback unless you will get an empty array.


A
Anik Islam Abhi

If you have complex objects in the array you can use filters? In situations where $.inArray or array.splice is not as easy to use. Especially if the objects are perhaps shallow in the array.

E.g. if you have an object with an Id field and you want the object removed from an array:

this.array = this.array.filter(function(element, i) {
    return element.id !== idToRemove;
});

This is how I like to do it. Using an arrow function it can be a one-liner. I'm curious about performance. Also worth nothing that this replaces the array. Any code with a reference to the old array will not notice the change.
z
zykadelic

Update: This method is recommended only if you cannot use ECMAScript 2015 (formerly known as ES6). If you can use it, other answers here provide much neater implementations.

This gist here will solve your problem, and also deletes all occurrences of the argument instead of just 1 (or a specified value).

Array.prototype.destroy = function(obj){
    // Return null if no objects were found and removed
    var destroyed = null;

    for(var i = 0; i < this.length; i++){

        // Use while-loop to find adjacent equal objects
        while(this[i] === obj){

            // Remove this[i] and store it within destroyed
            destroyed = this.splice(i, 1)[0];
        }
    }

    return destroyed;
}

Usage:

var x = [1, 2, 3, 3, true, false, undefined, false];

x.destroy(3);         // => 3
x.destroy(false);     // => false
x;                    // => [1, 2, true, undefined]

x.destroy(true);      // => true
x.destroy(undefined); // => undefined
x;                    // => [1, 2]

x.destroy(3);         // => null
x;                    // => [1, 2]

C
Community

You should never mutate your array as this is against the functional programming pattern. You can create a new array without referencing the one you want to change data of using the ECMAScript 6 method filter;

var myArray = [1, 2, 3, 4, 5, 6];

Suppose you want to remove 5 from the array, you can simply do it like this:

myArray = myArray.filter(value => value !== 5);

This will give you a new array without the value you wanted to remove. So the result will be:

 [1, 2, 3, 4, 6]; // 5 has been removed from this array

For further understanding you can read the MDN documentation on Array.filter.


E
Edric

You can do a backward loop to make sure not to screw up the indexes, if there are multiple instances of the element.

var myElement = "chocolate"; var myArray = ['chocolate', 'poptart', 'poptart', 'poptart', 'chocolate', 'poptart', 'poptart', 'chocolate']; /* Important code */ for (var i = myArray.length - 1; i >= 0; i--) { if (myArray[i] == myElement) myArray.splice(i, 1); } console.log(myArray);

Live Demo


t
tagurit

A more modern, ECMAScript 2015 (formerly known as Harmony or ES 6) approach. Given:

const items = [1, 2, 3, 4];
const index = 2;

Then:

items.filter((x, i) => i !== index);

Yielding:

[1, 2, 4]

You can use Babel and a polyfill service to ensure this is well supported across browsers.


Note that .filter returns a new array, which is not exactly the same as removing the element from the same array. The benefit of this approach is that you can chain array methods together. eg: [1,2,3].filter(n => n%2).map(n => n*n) === [ 1, 9 ]
Great, if I have 600k elements in array and want to remove first 50k, can you imagine that slowness? This is not solution, there's need for function which just remove elements and returns nothing.
@Seraph For that, you'd probably want to use splice or slice.
@bjfletcher Thats even better, in process of removal, just allocate 50K elements and throw them somewhere. (with slice 550K elements, but without throwing them from the window).
I'd prefer bjfletcher's answer, which could be as short as items= items.filter(x=>x!=3). Besides, the OP didn't state any requirement for large data set.