JavaScript exploration: Object

ECMAScript is a highly abstract object-oriented language.

ECMAScript is a highly abstract object-oriented language used to process Objects. Of course, there are also basic types, but if necessary, you also need to convert them into object objects for use.

An object is a collection of properties and has a single prototype object. The prototype may be either an object or the null value.

An Object is a set of attributes and has a separate prototype object [prototype object]. This prototype object [prototype Object] can be an object or a null value.

Let's take an example of a basic Object. First, we need to know that the prototype of an Object is a reference to the internal [prototype] attribute.

But in general, we will use __ <内部属性名> _ Underline to replace double parentheses, such as _ proto _ (this is the implementation of prototype concepts by some script engines such as SpiderMonkey, although not standard ).

var foo = {  x: 10,  y: 20};

The above code foo object has two explicit attributes: [explicit own properties] and an implicit _ proto _ attribute [implicit _ proto _ property]. the prototype pointing to foo.

A basic object containing a prototype

Why is prototype required? Let's consider the concept of prototype chain to answer this question.

Additional reading

The topic list of this article is as follows:

1. How should we understand the working principle of the JavaScript engine?
2. JavaScript exploration: the importance of writing maintainable code
3. JavaScript exploration: exercise caution when using global variables
4. JavaScript exploration: var pre-parsing and side effects
5. JavaScript exploration: for Loop (for Loops)
6. JavaScript exploration: for-in loop (for-in Loops)
7. Exploring JavaScript: Prototypes is too powerful
8. JavaScript: eval () is the devil"
9. JavaScript exploration: Using parseInt () for Numerical Conversion
10. Exploring JavaScript: Basic coding specifications
11. JavaScript exploration: function declaration and function expression
12. JavaScript exploration: Name function expressions
13. JavaScript: function name in the debugger
14. JavaScript: JScript Bug
15. JavaScript exploration: Memory Management of JScript
16. Exploring JavaScript: SpiderMonkey's quirks
17. JavaScript exploration: an alternative solution to naming function expressions
18. JavaScript exploration: Object
19. JavaScript exploration: Prototype chain
20. JavaScript exploration: Constructor
21. JavaScript probing: executable context Stack
22. Execution context 1: Variable object and activity object
23. Execution context 2: Scope chain Scope Chains
24. Execution context 3: Closure Closures
25. Execution context 4: This pointer
26. Exploring JavaScript: Powerful prototype and prototype chain
27. JavaScript Functions 1: function declaration
28. JavaScript function 2: function expressions
29. JavaScript function 3: function expressions in a group
30. JavaScript function 4: function Constructor
31. JavaScript variable object 1: VO Declaration
32. JavaScript variable object 2: VO in different execution contexts
33. JavaScript variable object 3: two stages of execution Context
34. JavaScript variable object IV: Variables
35. Property of the JavaScript variable object __parent _
36. JavaScript scope chain 1: Scope chain Definition
37. JavaScript scope chain 2: function Lifecycle
38. JavaScript scope chain 3: Scope chain features
39. JavaScript closure 1: Introduction to closures
40. JavaScript closure 2: Implementation of closure
41. JavaScript closure 3: Closure usage

This article is available at http://www.nowamagic.net/librarys/veda/detail/1640.