Javascript learning notes (8) javascript objects

& Nbsp; I read some articles about javascript objects yesterday. Here are some of my learning experiences and experiences. I hope to discuss them with you! 1. the built-in objects in javascript include built-in objects in addition to their own, such as the following familiar objects: ArrayDateMathStringRegExp ......

 
 
I read some articles about javascript objects yesterday. Here are some of my learning experiences and experiences. I hope to discuss them with you!
1. built-in objects in javascript
In addition to built-in objects in javascript, we are familiar with the following objects:
Array
Date
Math
String
RegExp
......
Each object has its own attributes and methods. For example, we often use attributes and methods.
Attribute: stringObject. length; arrayObject. length ;......
Method: stringObject. indexOf (); stringObject. splite (); stringObject. substr (); arrayObject. concat (); arrayObject. push (); arrayObject. join ();......
2. How to customize objects and add attributes and Methods
A. Create with the keyword "new"
Var newObject = new Object (); // create a new class
NewObject. name = "new object"; // Add a name attribute
NewObject. say = function () {// Add the say () method
Alert (this. name); // output new object
}
For the above creation method, we can use the JSON (JavaScript Object Notation) method to abbreviated as the following code:
Var newObject = {
Name: "new object ";
Say: function (){
Alert (this. name );
}
};
We use the JSON data format to create a more complex object.
Var company = {
Name: "tuanzz ",
Product: "groupon ",
Address: {province: "Hubei", city: "wuhan "},
Person :[
{Name: "zhangchen", age: "23 "},
{Name: "luomi", age: "23 "},
],
Readme: function (){
Alert ("My name is" + this. person [0]. name + "and" + this. person [0]. age + "years old ");
}
};
Company. readme (); // output My name is zhangchen and 23 years old;
We can see that the Code not only looks very elegant for the objects created in JSON data format.
The JSON format is the list of projects included with the large "{}". Each project is separated by a comma (,), and the project is a colon (:):. This is a typical dictionary representation, and again shows that the objects in JavaScript are dictionary structures. No matter how complex an object is, it can be created and assigned a value by a JSON code.
B. Create objects through Constructors
Function objectFun (name ){
This. name = name;
This. say = function (){
Alert (this. name );
}
}
Var newObject = new objectFun ("zhangchen ");
NewObject. say (); // output zhangchen
First, create an objectFun () function, which defines attributes and Methods. Here we can regard objectFun as a class (in javascript, a function is an object), and then create an object through the new instance, newObject also has attributes and methods in the parent class.
We can use the following code to check whether a function is an object:
// Common functions
Function say (s ){
Alert (s );
}
Say ("hi ");
// Assign an attribute to a function object. A function is an object.
Say. test = "it can work? ";
Alert (say. test); // output it can work?
How to Understand the above method of creating objects? Let's look at the following code:
Function objectFun (name ){
This. name = name;
This. say = function (){
Alert (this. name );
}
}
Var newObject = new Object (); // create an empty Object
ObjectFun. call (newObject, "zhangchen"); // call the objectFun function using newObject as the this parameter
NewObject. say ("zhangchen"); // output zhangchen
First, create a newObject. newObject is used as the this parameter to call the objectFun function. After talking about this, we can use objectFun as the constructor.

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