What is Splice in JavaScript ?

In JavaScript, splice() is a method that can be used to change the contents of an array by removing or replacing existing elements and/or adding new elements. It is a versatile method that allows you to modify arrays in-place.

Syntax:

array.splice(startIndex, deleteCount, item1, item2, ...);

Parameters:

• startIndex: The index at which to start changing the array. If negative, it counts from the end of the array.
• deleteCount: The number of elements to remove from the array, starting at startIndex. If set to 0, no elements are removed.
• item1, item2, ...: The elements to add to the array, starting at the startIndex.

Example: Here is the basic example of the Array splice() method.

Javascript

let webDvlop = ["HTML", "CSS", "JS", "Bootstrap"];

console.log(webDvlop);

// Add 'React_Native' and 'Php' after removing 'JS'.
let removed = webDvlop.splice(2, 1, 'PHP', 'React_Native')

console.log(webDvlop);
console.log(removed);

// No Removing only Insertion from 2nd
// index from the ending
webDvlop.splice(-2, 0, 'React')
console.log(webDvlop)

Output

[ 'HTML', 'CSS', 'JS', 'Bootstrap' ]
[ 'HTML', 'CSS', 'PHP', 'React_Native', 'Bootstrap' ]
[ 'JS' ]
[ 'HTML', 'CSS', 'PHP', 'React', 'React_Native', 'Bootstrap' ]