How to define a list array in javascript

In JavaScript, an array (Array) is a container that stores elements. Each element has an index (index), which determines the position of the element in the array. Array is a very important data type that is often used in development.

Define an array in the following three ways:

1. Define the array directly

You can use the following syntax to directly define the array:

let arr = [1, 2, 3];

This array contains three elements 1, 2, and 3. In this way of definition, square brackets ([ ]) can be used to define an array.

2. Define an array with a fixed size

You can use the following syntax to define an array with a fixed size:

let arr = new Array(3);

This array contains 3 undefined element. In this way of definition, you need to use the new keyword and specify the size of the array.

3. Use the Array.of() method

You can use the Array.of() method to directly define an array:

let arr = Array.of(1, 2, 3);

This array contains three elements 1, 2, and 3. In this way of definition, you need to use the Array.of() method.

In addition to the above three methods, you can also use loop statements to define arrays. For example, the following code defines an array containing integers from 1 to 10:

let arr = [];
for (let i = 1; i <= 10; i++) {
  arr.push(i);
}

This array contains 10 elements: 1, 2, 3, 4, 5, 6, 7, 8, 9 , and 10.

Summary

The above are the three common ways to define arrays. Arrays can be used to easily store and access multiple values ​​and are a very commonly used data type. In actual development, you need to choose the appropriate way to define and operate arrays according to the situation.

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