What Does Shift do in JavaScript?

One of its important functions is the “.shift in JavaScript” function, which is generally used to employ arrays.

In this guide, you are going learn the complexity of the shift function, exploring its purpose, syntax, examples, and practical applications.

What is Shift in JavaScript?

The shift function in JavaScript is an array method that eliminates the first element from an array and returns that element.

This process also shifts the remaining elements in one position towards the beginning of the array, decreasing the array’s length by one.

Syntax for Shift in JavaScript

let shiftedElementSample = array.shift();

This syntax is composed of two:

  • array is the array from which you want to eliminate the first element.
  • shiftedElementSample is the variable that will keep the removed element.

Practical Applications of the Shift Function

The shift function finds its application in different cases, such as:

Implementing Queues

Queues follow the “first in, first out” (FIFO) principle. The shift function helps maintain this action by eliminating the oldest item from the queue.

Processing Lists

When handling lists of items, the shift function is useful for successively processing each item in the list.

Creating Slideshows

For making slideshows or carousels, the shift function assists in cycling through the images by eliminating the displayed image from the array.

Dynamic Data Updates

In dynamic applications, where data is continuously modified, the shift function can be used to handle the display of the most recent data.

Examples of Using the Shift Function

Let’s discuss a few examples to understand the practical implementation of the shift function:

Example of Implementing a Queue

let value = ["first", "second", "third"];
let dequeuedElementValue = value.shift();


Example of Creating a Slideshow

let imagesValue = ["image1.jpg", "image2.jpg", "image3.jpg"];
let currentImageValue = imagesValue.shift();



What happens if you use the shift function on an empty array?

Using the shift function on an empty array returns undefined and does not modify the array.

Can the shift function be used with other data types?

No, the shift function is specially designed for arrays and does not work with other data types.

Does the shift function affect the original array?

Yes, the shift function directly changes the original array by removing the first element.

Can you combine shift with other array methods?

Yes, you can combine the shift function with other array methods to perform complex operations on arrays.


In JavaScript, a shift function is a powerful tool for array manipulation, specifically when dealing with dynamic data and ordered processing.

By understanding its functionality and different applications, you can use the shift function effectively in your web development projects.

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