JavaScript - Delete an Item From an Array

In Javascript, we do not have any array.remove() method for deleting the element. Here are the various methods we can delete an item from an array using JavaScript.

1. Using for loop and push() Method

The push() method will not mutate the original array. First, you have to create an empty() array and then loop over the new array and push only those elements that you want.

let a1 = ['gfg', 'GFG', 'g', 'GeeksforGeeks'];
const a2 = [];

for (let i = 0; i < a1.length; i++) {
    if (a1[i] !== 'GFG') {
        a2.push(a1[i]);
    }
}
console.log(a1);
console.log(a2); 

[ 'gfg', 'GFG', 'g', 'GeeksforGeeks' ]
[ 'gfg', 'g', 'GeeksforGeeks' ]

In this example

• It uses a for loop to iterate through arr.
• If an element is not 'GFG', it's added to a2.
• Finally, it prints both the original arr and the modified a2.

2. Using Pop() Method

Pop() method is used to delete the last element of the array and return the deleted item as an output.

let a1 = ['gfg', 'GFG', 'g', 'GeeksforGeeks'];
let a2 = a1.pop();
console.log(a2);
console.log(a1.length)

GeeksforGeeks
3

In this example

• arr.pop() removes and returns the last element of the array ('GeeksforGeeks').
• The new length of arr (after removal) is logged.

3. Using shift() Method

Shift() method is used to delete an element from the beginning of an array.

let a1 = ['gfg', 'GFG', 'g', 'GeeksforGeeks'];
let a2 = a1.shift();
console.log(a2);
console.log(a1.length)

gfg
3

In this example

• a1.shift() removes and returns the first element of the array ('gfg').
• The new length of arr (after removal) is logged.

4. Using splice() Method

Splice() method is used for deleting the existing element or replacing the content of the array by removing/adding a new element.

let a = ["apple", "banana", "grapes", "strawberry"];
const rem = a.splice(2, 2, "guava");

console.log(rem);
console.log(a.length);
console.log(a);     

[ 'grapes', 'strawberry' ]
3
[ 'apple', 'banana', 'guava' ]

In this example

• a.splice(2, 2, "guava"): This removes 2 elements from index 2 ("grapes" and "strawberry") and adds "guava" in their place.
• The removed elements are stored in rem, and a.length reflects the new size of the array after the change.

5. Using filter() Method

filter() method returns the new array. Those array element that satisfies the condition of function is only passed on to the new array.

const a = [2, 7, 9, 15, 19];

function isPrime(n) {
    for (let i = 2; n > i; i++) {
        if (n % i === 0) {
            return false;
        }
    }
    return n > 1;
}

console.log(a.filter(isPrime));

[ 2, 7, 19 ]

In this example

• isPrime(n): Returns true if n is prime, otherwise false.
• a.filter(isPrime): Filters array and returns a new array containing only the prime numbers from array.

6. Using delete Operator

Delete operator is more specifically used to delete JavaScript object properties.

const a = [2, 7, 9, 15, 19];
delete a[3];
console.log(a);

[ 2, 7, 9, <1 empty item>, 19 ]

• delete arr[3]: Removes the element at index 3 (value 15), but the array length remains unchanged, and the index is left with an undefined value.

7. Using Lodash _.remove() Method

The _.remove() method is used to remove all elements from the array that predicate returns True and returns the removed elements.

const _ = require("lodash"); 
let a = [1, 2, 3, 4, 5];
let even = _.remove(a, function (n) {
    return n % 2 == 0;
});

console.log('Original Array ', a);
console.log('Removed element array ', even);

Output:

Original Array  [ 1, 3, 5 ]
Removed element array  [ 2, 4 ]

In this example

• _.remove(a, function(n) { return n % 2 == 0; }): Removes all even numbers from a and returns the removed elements in a new array (even).
• a: The original array is modified in place.
• even: Contains the even numbers that were removed.

8. Using Lodash _.pullAt method

Using Lodash's _.pullAt method removes elements from an array at specified indices. It modifies the original array, making it efficient for targeted deletions.

const _ = require('lodash');

let a = ['a', 'b', 'c', 'd', 'e'];
_.pullAt(a, [1, 3]);
console.log(a); 

Output:

['a', 'c', 'e']

In this example

• _.pullAt(a, [1, 3]): This removes the elements at indices 1 and 3 from the array (i.e., 'b' and 'd').
• The function modifies the original array directly, removing the specified elements.