JavaScript object

JavaScript objects are data that have properties and methods.

---

Real life objects, properties and methods

In real life, a car is an object.

The object has its properties, such as weight and color, etc., and the methods include start and stop, etc.:

All cars have these methods, but the time they are executed is different. .All cars have these attributes, but the attributes of each car are different.

---

JavaScript Object

In JavaScript, almost everything is an object.

In JavaScript, objects are very important. When you understand objects, you can understand JavaScript.

---

#You have learned about JavaScript variable assignment.

The following code sets the value of variable car to "Fiat":

var car = "Fiat";

Object Also a variable, but an object can contain multiple values (multiple variables).

var car = {type:"Fiat", model:500, color:"white"};

In the above example, 3 values ("Fiat ", 500, "white") is assigned to the variable car.

In the above example, 3 variables (type, model, color) are assigned to the variable car.

Tip: JavaScript objects are containers for variables.

---

Object definition

You can define and create JavaScript objects using characters:

Example

     
  
创建 JavaScript 对象。
 
   

Run the program and try it

---

Define JavaScript objects to span multiple lines, spaces and newlines are not necessary:

Example

     
  
创建 JavaScript 对象。
 
   

Run the program and try it

---

Object properties

It can be said that "JavaScript objects are containers of variables".

However, we usually think of "JavaScript objects as containers of key-value pairs".

Key-value pairs are usually written as name : value (key and value are separated by colon).

Key-value pairs in JavaScript objects are often called object properties.

Tip: JavaScript objects are containers for property variables.

---

The object key-value pair is written similar to:

• Associative array in PHP

• Dictionary in Python

• Hash table in C language

• Hash map in Java

• Hash tables in Ruby and Perl

---

Accessing object properties

You can access object properties in two ways:

Method one

     
  
 有两种方式可以访问对象属性： 
 
 你可以使用 .property 或 ["property"]. 
 
   

Run the program to try it

---

Method two

     
  
 有两种方式可以访问对象属性: 
 
 你可以使用 .property 或 ["property"]。 
 
   

Run the program to try it

---

Accessing object methods

##You can create object methods using the following syntax:

methodName : function() { code lines }

You can access object methods using the following syntax:

objectName.methodName()

Usually fullName() is used as a method of the person object, and fullName is used as a property.

There are many ways to create, use and modify JavaScript objects.

There are also many ways to create, use and modify properties and methods.