JavaScript mode Reading Notes Chapter 1 code reuse Mode

JavaScript mode Reading Notes Chapter 1 code reuse Mode
It mainly uses code inheritance for reuse. 1. Use class inheritance. -1. class-based inheritance: inheritance is implemented based on the class method, that is, the so-called class-based inheritance.
-2. class inheritance: You can use the constructor (child) to obtain the parent attributes and create an object.

<script>//parent function Parent(name){this.name = name || 'Adam'; } Parent.prototype.say = function(){ return this.name; } //child function Child(name){  }// Implement inheritance here and implement it by yourself inherit(Child, Parent);   </script>

-3, default mode

 // Default mode function inherit(C, P){C.prototype = new P(); }  var kid = new Child();Console. log (kid. say (); // output Adam

-4. Borrow Constructor
Borrow the parent class constructor, which passes the sub-object to bind to this and forwards any parameters.

<script>// Parent Constructorfunction Article(){this.tags = ['js', 'css'];}var article = new Article(); function BlogPost(){ }BlogPost. prototype = article; // get a reference to the corresponding objectvar blog = new BlogPost(); function StaticPost(){Article. call (this); // get a copy of the corresponding object Member, equivalent to generating the same member variable in this object}var page = new StaticPost();console.log(article.hasOwnProperty('tags'));//trueconsole.log(blog.hasOwnProperty('tags'));//falseconsole.log(page.hasOwnProperty('tags'));//true   </script>

-5. Borrow and set the prototype.

<script>function Child(a, b, c, d){Parent. apply (this, arguments); // obtain the member variable of the Parent class by borrow} Child. prototype = new Parent (); // obtain the method of the Parent class through this   </script>

<script>function Parent(name){this.name = name || "Tom";}Parent.prototype.say = function(){return this.name;}function Child(name){Parent.apply(this, arguments);} Child.prototype = new Parent(); var kid = new Child("Child");console.log(kid.name);//childconsole.log(kid.say());//childdelete kid.name;console.log(kid.say());//Tom   </script>

-6. Sharing prototype

function inherit(C, P){      C.prototype = P.prototype;}

If a subclass below the inheritance chain modifies the prototype, it will affect all objects on the prototype chain. -7. Temporary Constructor

function inherit(C, P){    var F = function(){};   F.prototype = P.prototype;   C.prototype = new F();}

-8, Klass a. All have a set of conventions on how to name class methods.
B. there are classes inherited from other classes.
C. You can access the parent class or superclass In the subclass.

 <script>var klass = function(Parent, props){var Child, F, i; // 1. New ConstructorChild = function(){if(Child.uber && Child.uber.hasOwnProperty("_construct")){Child.uber._construct.apply(this, arguments);} if(Child.prototype.hasOwnProperty("_construct")){Child.prototype._construct.apply(this, arguments);}}; // 2. InheritParent = Parent || Object;F = function(){}; F.prototype = Parent.prototype;Child.prototype = new Child();Child.uber = Parent.prototype;Child.prototype.constructor = Child; // 3. Add Implementation Methodfor(i in props){if(props.hasOwnProperty(i)){Child.prototype[i]= props[i];}} return Child; };   </script>

Code reuse is the purpose, and inheritance is only one of the methods to achieve this goal.