Joining Arrays in JavaScript

In JavaScript, as in many other scripting and programming languages, we often need to use arrays. Furthermore, it is often useful to combine the elements of an array into a single string. In PHP, for example, the implode function is used to join the elements of an array. In this context, “implode” can be viewed as a synonym for “join”. In JavaScript, however, there is no “implode” function; instead, there is a built-in “join” function that performs the same task. In this article, we are going to examine JavaScript’s join function in some detail.


The join function concatenates the elements of an array into a single string. The syntax for the join function is as follows:


Here, separator is the string or string used to separate elements of the array; it can be any character or string, such as the space character (i.e., “ ”) or a string like “xyz”, but a comma is used as the default.


Now, let’s look at some examples.

First, we declare an array of letters.

let arr = ["a", "b", "c", "d", "f"]

We can call the join function for this array without providing a separator as follows, which will return the all characters from the array separated by commas:

Now, let’s see what will happen if we provide the space character as a separator:

Here, in the string returned, the array elements are separated by the space character instead of a comma.

We can provide any character or string as a separator. If we want to put “ and ” between the array’s elements, we can do that as follows:

Here, every alphabet is separated by the “ and ”, which might be very useful for certain applications. Any string can be provided as a separator for joining an array’s elements in the same way.


This article explains JavaScript’s join function and provides some useful examples. We can provide any string we want as a separator to join an array’s elements.

We hope you found this article useful and continue using to learn about JavaScript.

About the author

Shehroz Azam

A Javascript Developer & Linux enthusiast with 4 years of industrial experience and proven know-how to combine creative and usability viewpoints resulting in world-class web applications. I have experience working with Vue, React & Node.js & currently working on article writing and video creation.