3 Uses of the Three Dots in JavaScript

Make your JavaScript code much more elegant

Photo by Clay Banks on Unsplash

If you read any modern JavaScript programs, you probably will meet one thing many times — the ellipsis. It is just three dots (…) which was introduced by ES6. Looks very simple and unremarkable? However, it changed JavaScript a lot.

Let’s feel it by a simple example:

Now, we have a string called author as following:

let author = "Yang"

How can we convert this string to an array including all the characters?

In C or C++, we need to define an array at first and then use a for loop to iterate all characters and add them into the array one by one.

In JavaScript, we just need one line of code:

let authorChar = [...author]

The ellipsis makes JavaScript much more elegant. Isn’t it?

In fact, the above example only shows the tip of the iceberg. This article will dive into 3 major uses of the three dots in JavaScript and show how they make JavaScript great.

1. Destructuring Assignment in JavaScript

This feature makes the assignment operation in JavaScript more elegant.