How to define arrays in js

There are two ways to define arrays in JavaScript: 1. Literal syntax: use square brackets [] to store element values. 2. Array constructor: Use new Array() to create an array. You can specify element values, array length, or copy an existing array. It is recommended to use literal syntax in general and use array constructors when you need to create an empty array or copy an existing array.

How to define arrays in JavaScript

Arrays are a commonly used data structure in JavaScript for storage An ordered series of values. In JavaScript, there are two common ways to define arrays:

1. Literal syntax

This is the simplest method, directly using square brackets [] and element values ​​to define the array:

<code class="javascript">const arr = ["苹果", "香蕉", "梨子"];</code>

2. Array constructor

This method uses the built-in new Array() constructor to create array. Here are some variations of defining an array using the array constructor:

• Using element values:

<code class="javascript">const arr = new Array("苹果", "香蕉", "梨子");</code>

• Using arrays Length:

<code class="javascript">const arr = new Array(3); // 创建一个长度为 3 的空数组</code>

• Use another array:

<code class="javascript">const originalArr = ["苹果", "香蕉", "梨子"];
const newArr = new Array(originalArr); // 复制 originalArr</code>

Which method to choose?

In most cases, it is recommended to use literal syntax because it is more concise and clear. However, you can use it if you need to use the array constructor to create an empty array or copy an existing array.

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