JavaScript Array splice() Method

JavaScript Array splice() Method is an inbuilt method in JavaScript that is used to change the contents of an array by removing or replacing existing elements and/or adding new elements. It modifies the original array and returns an array of the removed elements.

Array splice() Syntax:

Array.splice( index, remove_count, item_list )

index: It is a required parameter. This parameter is the index from which the modification of the array starts (with the origin at 0). This can be negative also, which begins after many elements counting from the end.
remove_count: The number of elements to be removed from the starting index.
items_list: The list of new items separated by a comma operator that is to be inserted from the starting index.

Return Value

While it mutates the original array in place, still it returns the list of removed items. In case there is no removed array it returns an empty array.

Array splice() 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' ]

Explanation:

This JavaScript code demonstrates manipulating an array `webDvlop`. Initially, it logs the array contents. Then, it removes “JS” from index 2 and inserts “PHP” and “React_Native” in its place, logging the modified array and the removed element. Lastly, it inserts “React” at the second-to-last index, logging the final array.

Array splice() Example

Here is another example of the Array splice() method.

Javascript

let languages = ['C++', 'Java', 'Html', 'Python', 'C'];
 
console.log(languages);
 
// Add 'Julia' and 'Php' after removing 'Html'.

let removed = languages.splice(2, 1, 'Julia', 'Php')
 
console.log(languages);
console.log(removed);
 
// No Removing only Insertion from 2nd index from the ending

languages.splice(-2, 0, 'Pascal')
console.log(languages)

Output

[ 'C++', 'Java', 'Html', 'Python', 'C' ]
[ 'C++', 'Java', 'Julia', 'Php', 'Python', 'C' ]
[ 'Html' ]
[
  'C++',    'Java',
  'Julia',  'Php',
  'Pascal', 'Python',
  'C'
]

Explanation:

This JavaScript code operates on an array `languages`. Initially, it logs the array contents. Then, it removes “Html” from index 2 and inserts “Julia” and “Php” in its place, logging the modified array and the removed element. Lastly, it inserts “Pascal” at the second-to-last index, logging the final array.

We have a complete list of Javascript Array methods, to check those please go through this Javascript Array Complete reference article.

Supported Browsers:

Article Tags :

JavaScript

Web Technologies

javascript-array

JavaScript-Methods