Js native inheritance

　　Inheritance is important in most languages. JavaScript is a prototype-based language, this means that the object can inherit directly from other objects. Here are some common js inheritance.

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1. Prototype inheritance chain

   function Father(){ 
    this.status = true; 
   } 
   Father.prototype.getSuper = function(){ 
    return this.status; 
   }; 
   function Son(){ 
    this.substatus = false; 
   } 
   //继承了 SuperType 
   Son.prototype = new Father(); 
   Son.prototype.getSub = function (){ 
    return this.substatus; 
   }; 
   var instance = new Son(); 
   alert(instance.getSuper()); //true

    

2. Borrowing constructor inheritance

   function Father(){ 
    this.colors = [1,2,3]; 
   } 
   function Son(){ 
    //继承了 Father
    Father.call(this); 
   } 
   var instance1 = new Son(); 
   instance1.colors.push(4); 
   alert(instance1.colors); //"1,2,3,4" 
   var instance2 = new Son(); 
   alert(instance2.colors); //"1,2,3"

    

3. A combination of inheritance

   function Father (name) { 
      the this .name = name; 
   } 
   Father.prototype.sayName = function () { 
     Alert ( the this .name); 
   }; 
   function Son (name, Age) { 
      // inherited properties 
     SuperType.call ( the this , name); 
      the this .age = Age; 
   }
    
   Son.prototype = new new father (); // prototype parent class subclasses directed 
   Son.prototype.constructor = son; // to point to themselves subclass constructor 
   Son.prototype. sayAge = function () { 
     Alert ( the this.age); 
   }; 
   var instance = new Son("lh", 19); 
   instance1.sayName(); //"lh"; 
   instance1.sayAge(); //19 
   

    

4. Prototypal inheritance

   function object(o){ 
     function F(){} 
     F.prototype = o; 
     return new F(); 
   }
   var person = { 
     name: "lh", 
     loves: ["a", "b", "c"] 
   }; 
   var anotherPerson = object(person); 
   anotherPerson.name = "Greg"; 
   anotherPerson.friends.push("d");  
   alert(person.loves); //"a,b,c,d"

    Object and method herein the Object.create () method analogous.

5. Parasitic inheritance

   function Object (O) { 
      function F. () {} 
     F.prototype = O; 
      return  new new F. (); 
   } 
   function createAnother (obj) { 
      var clone = Object (obj); // Create a new object by calling the function 
     clone. = say function () { // for the method of adding the object 
     Alert ( "Hi" ); 
     }; 
     return clone; // return the object 
   }
    var Person = { 
     name: "LH" , 
     Loves: [ "A", "B "," C " ] 
   }; 
   var anotherPerson = createAnother(person); 
   anotherPerson.say(); //"hi"

    

6. Combined parasitic inheritance

   function inheritPrototype(son, father){ 
     var prototype = Object.create(father.prototype); 
      son.prototype = prototype; 
   　　prototype.constructor = son;
   }
   function Father(name){ 
    this.name = name; 
   } 
   Father.prototype.sayName = function(){ 
    alert(this.name); 
   }; 
   function Son(name, age){ 
    Father.call(this, name); 
    this.age = age; 
   } 
   inheritPrototype(Son, Father); 
   

    

7. Use es6 achieve

   class Father{
     constructor(x, y) {
       this.x = x;
       this.y = y;
     }
   }
   class son extends Father{
     constructor(x, y, age) {
       super(x, y); // 调用父类的constructor(x, y)
       this.age= age;
     }
     toString() {
       return this.color + ' ' + super.toString(); // 调用父类的toString()
     }
   }

　　　　Subclass inherits the parent class constructor must first call the super () method to access this, otherwise it will error.