Home Web Front-end Front-end Q&A Can objects be included in a javascript array?

Can objects be included in a javascript array?

Mar 28, 2022 pm 04:20 PM
javascript object array

Javascript arrays can contain objects. A JavaScript array is a collection of data arranged in order. The array can contain any type of data, that is, there is no limit on the type of array elements, which can be numbers, strings, arrays, Object, etc.

Can objects be included in a javascript array?

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

Javascript arrays can contain objects.

An array (Array) is a collection of data arranged in order. Each value in the array is called an element, and the array can contain any type of data.

Example:

let arr = [1,'hello',true,[1,2],{name: 'Bob',age:20}];
console.log(arr);
Copy after login

Can objects be included in a javascript array?

It can be seen that when defining an array and assigning a value, the value of the array element can be a number, string, or Boolean Value, array, object and other types.

Simply put, there is no restriction on the type of array elements.

Extended knowledge: Pseudo-class array

Pseudo-class array, also known as class array, is an object similar to an array structure. To put it simply, the object's attribute name is a non-negative integer, starting from 0, increasing in order, and including the length attribute. It should also ensure that its value is dynamically consistent with the number of ordered subscript attributes to facilitate pseudo-classes. Array iteration. The well-known jQuery object is a pseudo-array.

Example

In the following example, obj is an object literal. When assigning it using an array subscript, JavaScript no longer treats it as an array subscript, but instead It is regarded as the property name of the object.

var obj = {};  //定义对象直接量
obj[0] = 0;
obj[1] = 1;
obj[2] = 2;
obj.length = 3;
console.log(obj["2"]);  //返回2
Copy after login

It is equivalent to an object literal.

var obj = {
    0 : 0,
    1 : 1,
    2 : 2,
    length : 3
};
Copy after login

Because numbers are illegal identifiers, you cannot use dot syntax to read and write attributes.

console.log(obj.0);
Copy after login

Instead, use square bracket syntax to read and write properties.

console.log(obj["2"]);
Copy after login

[Related recommendations: javascript video tutorial, web front-end

The above is the detailed content of Can objects be included in a javascript array?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Will R.E.P.O. Have Crossplay?
1 months ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to remove duplicate elements from PHP array using foreach loop? How to remove duplicate elements from PHP array using foreach loop? Apr 27, 2024 am 11:33 AM

The method of using a foreach loop to remove duplicate elements from a PHP array is as follows: traverse the array, and if the element already exists and the current position is not the first occurrence, delete it. For example, if there are duplicate records in the database query results, you can use this method to remove them and obtain results without duplicate records.

The Art of PHP Array Deep Copy: Using Different Methods to Achieve a Perfect Copy The Art of PHP Array Deep Copy: Using Different Methods to Achieve a Perfect Copy May 01, 2024 pm 12:30 PM

Methods for deep copying arrays in PHP include: JSON encoding and decoding using json_decode and json_encode. Use array_map and clone to make deep copies of keys and values. Use serialize and unserialize for serialization and deserialization.

PHP array key value flipping: Comparative performance analysis of different methods PHP array key value flipping: Comparative performance analysis of different methods May 03, 2024 pm 09:03 PM

The performance comparison of PHP array key value flipping methods shows that the array_flip() function performs better than the for loop in large arrays (more than 1 million elements) and takes less time. The for loop method of manually flipping key values ​​takes a relatively long time.

How to convert MySQL query result array to object? How to convert MySQL query result array to object? Apr 29, 2024 pm 01:09 PM

Here's how to convert a MySQL query result array into an object: Create an empty object array. Loop through the resulting array and create a new object for each row. Use a foreach loop to assign the key-value pairs of each row to the corresponding properties of the new object. Adds a new object to the object array. Close the database connection.

Application of PHP array grouping function in data sorting Application of PHP array grouping function in data sorting May 04, 2024 pm 01:03 PM

PHP's array_group_by function can group elements in an array based on keys or closure functions, returning an associative array where the key is the group name and the value is an array of elements belonging to the group.

Best Practices for Deep Copying PHP Arrays: Discover Efficient Methods Best Practices for Deep Copying PHP Arrays: Discover Efficient Methods Apr 30, 2024 pm 03:42 PM

The best practice for performing an array deep copy in PHP is to use json_decode(json_encode($arr)) to convert the array to a JSON string and then convert it back to an array. Use unserialize(serialize($arr)) to serialize the array to a string and then deserialize it to a new array. Use the RecursiveIteratorIterator to recursively traverse multidimensional arrays.

What is the difference between arrays and objects in PHP? What is the difference between arrays and objects in PHP? Apr 29, 2024 pm 02:39 PM

In PHP, an array is an ordered sequence, and elements are accessed by index; an object is an entity with properties and methods, created through the new keyword. Array access is via index, object access is via properties/methods. Array values ​​are passed and object references are passed.

PHP array multi-dimensional sorting practice: from simple to complex scenarios PHP array multi-dimensional sorting practice: from simple to complex scenarios Apr 29, 2024 pm 09:12 PM

Multidimensional array sorting can be divided into single column sorting and nested sorting. Single column sorting can use the array_multisort() function to sort by columns; nested sorting requires a recursive function to traverse the array and sort it. Practical cases include sorting by product name and compound sorting by sales volume and price.

See all articles