How can I remove a specific item from an array?
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 removingexisting 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); 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;}// Usageconsole.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;}
Edited on 2016 October
- Do it simple, intuitive and explicit (Occam's razor)
- Do it immutable (original array stay 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 using the filter polyfill from Mozilla.
Removing item (ECMA-262 Edition 5 code aka oldstyle JavaScript)
var value = 3var 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 = 3let 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 45 version, Firefox before 22 version, and Safari before 10 version. 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 47 version, Firefox before 43 version, Safari before 9 version, and Edge before 14 version so here is polyfill from Mozilla.
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.jsexport function remove(...forDeletion) { return this.filter(item => !forDeletion.includes(item))}// main.jsimport { 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.prototypearr = arr::remove(2, 3, 5)console.log(arr)// [ 1, 4 ]Reference
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];