What do square brackets mean in js

In JavaScript, square brackets ([]) represent an array, which is a data structure that is an ordered collection of elements. You can create arrays using literal syntax or the Array() constructor, and use square bracket syntax to access and modify elements by index value. JavaScript also provides a variety of methods for manipulating and modifying arrays, such as push(), pop(), shift(), and unshift().

JavaScript square brackets represent an array

In JavaScript, square brackets ([]) represent an array. An array is a data structure used to store elements of an ordered collection.

Definition of array

An array can store various data types, including strings, numbers, Boolean values, objects and even other arrays. Elements in an array are accessed by index value, starting from 0.

Creation of arrays

You can create arrays in two ways:

• Literal syntax: Use square brackets directly to specify elements, for example:

  <code class="js">const myArray = ["John", 25, true];</code>

• Array() constructor: Use Array() constructor, for example:

  <code class="js">const myArray = new Array("John", 25, true);</code>

Accessing array elements

You can access array elements by index value, using square bracket syntax:

<code class="js">console.log(myArray[0]); // "John"
console.log(myArray[1]); // 25
console.log(myArray[2]); // true</code>

Modify array elements

Modify array elements using the same square bracket syntax:

<code class="js">myArray[0] = "Jane";
console.log(myArray[0]); // "Jane"</code>

Array methods

JavaScript provides a variety of methods for operating and modifying arrays , for example:

• push(): Add elements to the end of the array
• pop():Remove elements from the end of the array
• shift(): Remove elements from the beginning of the array
• unshift(): Add elements to the beginning of the array
• join(): Connect array elements into a string
• slice():Copy the specified range of elements from the array

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