How to remove item from array by value?

Question

Is there a method to remove an item from a JavaScript array?

Given an array:

var ary = ['three', 'seven', 'eleven'];

I would like to do something like:

removeItem('seven', ary);

I've looked into splice() but that only removes by the position number, whereas I need something to remove an item by its value.

Answer 1

Non-destructive removal:

function removeArrayValue(array, value)
{
    var thisArray = array.slice(0); // copy the array so method is non-destructive

    var idx = thisArray.indexOf(value); // initialise idx

    while(idx != -1)
    {
        thisArray.splice(idx, 1); // chop out element at idx

        idx = thisArray.indexOf(value); // look for next ocurrence of 'value'
    }

    return thisArray;
}

Answer 2

If you have unique values in your array and ordering doesn't matter, you can use Set, and it has delete:

var mySet = new Set(['foo']);
mySet.delete('foo'); // Returns true.  Successfully removed.
mySet.has('foo');    // Returns false. The "foo" element is no longer present.

Answer 3

Seeing as there isn't a pretty one, here's a simple and reusable ES6 function.

const removeArrayItem = (arr, itemToRemove) => {
  return arr.filter(item => item !== itemToRemove)
}

Usage:

const items = ['orange', 'purple', 'orange', 'brown', 'red', 'orange']
removeArrayItem(items, 'orange')

Answer 4

//This function allows remove even array from array
var removeFromArr = function(arr, elem) { 
    var i, len = arr.length, new_arr = [],
    sort_fn = function (a, b) { return a - b; };
    for (i = 0; i < len; i += 1) {
        if (typeof elem === 'object' && typeof arr[i] === 'object') {
            if (arr[i].toString() === elem.toString()) {
                continue;
            } else {                    
                if (arr[i].sort(sort_fn).toString() === elem.sort(sort_fn).toString()) {
                    continue;
                }
            }
        }
        if (arr[i] !== elem) {
            new_arr.push(arr[i]);
        }
    }
    return new_arr;
}

Example of using

var arr = [1, '2', [1 , 1] , 'abc', 1, '1', 1];
removeFromArr(arr, 1);
//["2", [1, 1], "abc", "1"]

var arr = [[1, 2] , 2, 'a', [2, 1], [1, 1, 2]];
removeFromArr(arr, [1,2]);
//[2, "a", [1, 1, 2]]

Answer 5

indexOf is an option, but it's implementation is basically searching the entire array for the value, so execution time grows with array size. (so it is in every browser I guess, I only checked Firefox).

I haven't got an IE6 around to check, but I'd call it a safe bet that you can check at least a million array items per second this way on almost any client machine. If [array size]*[searches per second] may grow bigger than a million you should consider a different implementation.

Basically you can use an object to make an index for your array, like so:

var index={'three':0, 'seven':1, 'eleven':2};

Any sane JavaScript environment will create a searchable index for such objects so that you can quickly translate a key into a value, no matter how many properties the object has.

This is just the basic method, depending on your need you may combine several objects and/or arrays to make the same data quickly searchable for different properties. If you specify your exact needs I can suggest a more specific data structure.

Answer 6

Check out this way:

for(var i in array){
    if(array[i]=='seven'){
        array.splice(i,1);
        break;
    }
}

and in a function:

function removeItem(array, item){
    for(var i in array){
        if(array[i]==item){
            array.splice(i,1);
            break;
        }
    }
}

removeItem(array, 'seven');