How to Remove Multiple Elements from Array in JavaScript?

Here are various methods to remove multiple elements from an array in JavaScript

1. Using filter() Method

The filter() method creates a new array with the elements that pass the condition. This method does not change the original array.

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
a = a.filter(x => !remove.includes(x));
console.log(a); 

In this example

• remove contains elements to be removed.
• filter() iterates over a and includes elements not in remove.
• includes() checks if an element is in the remove array.

2. Using splice() in a Loop

The splice() method can be used to Iterate through the array and remove elements using splice().

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
for (let i = a.length - 1; i >= 0; i--) {
    if (remove.includes(a[i])) {
        a.splice(i, 1);
    }
}
console.log(a); 

In this example

• Loop backward to avoid index shifting.
• splice(i, 1) removes the element at index i.
• includes() checks if the element is in Remove.

3. Using Set for Faster Lookups

Set is Used to convert the elements to be removed into a Set for better performance.

let a = [1, 2, 3, 4, 5];
let remove = new Set([2, 4]);
a = a.filter(x => !remove.has(x));
console.log(a); 

In this example

• Set allows O(1) lookup time compared to O(n) for arrays.
• has() checks if the element exists in Remove.

4. Using reduce() Method

The reduce() method can be used to build a new array while excluding elements based on the specified indexes.

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
a = a.reduce((acc, x) => {
    if (!remove.includes(x)) acc.push(x);
    return acc;
}, []);
console.log(a); 

In this example

• Accumulates elements not in Remove into a new array.
• includes() checks membership in Remove.

5. Using forEach()

A forEach() loop through the array and selectively add elements to a new array.

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
let res = [];
a.forEach(x => {
    if (!remove.includes(x)) res.push(x);
});
console.log(res); 

[ 1, 3, 5 ]

In this example

• forEach() iterates over a.
• Elements not in Remove are pushed to res.

6. Using concat() and filter()

The concat() and filter() is concatenate filtered elements directly into a new array.

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
let res = [].concat(a.filter(x => !remove.includes(x)));
console.log(res);

In this example

• filter() removes unwanted elements.
• concat() ensures result is a new array (optional for immutability).

7. Using splice() with Index Lookup

Find indices of elements to remove, then use splice().

let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
remove.forEach(x => {
    let index = a.indexOf(x);
    if (index !== -1) a.splice(index, 1);
});
console.log(a);

[ 1, 3, 5 ]

In this example

• indexOf() finds the index of an element.
• splice() removes the element by index.

8. Using Lodash's difference()

Utilize Lodash's utility function to exclude unwanted elements from the array.

let _ = require('lodash');
let a = [1, 2, 3, 4, 5];
let remove = [2, 4];
a = _.diff(a, remove);
console.log(a); 

In this example

• difference() returns elements in a not in Remove.
• Convenient for large arrays.

Which Approach You Should Use