浅析 JS 的继承

一、原型的继承

function superType(name){
	this.name = name;
}
superType.prototype.sayName = function(){
	console.log(this.name)
}

function subType(name,age){
        // 继承属性
	superType.call(this,name);
	this.age = age;
}

// 继承方法
subType.prototype = new superType();

subType.prototype.sayAge = function(){
	console.log(this.age)
}

// subType 实例 同时拥有 name，age属性，sayName sayAge方法
var Alias = new subType("Alias",18)
Alias.sayName(); // "Alias"
Alias.sayAge()   // 18
}

二、class 的继承

class SuperType {
   // constructor
   constructor(name){
       this.name = name;
   }
   // getter
   get city(){
      return "ShangHai"
   }
   // Methods
   sayName(){
      console.log(this.name)	
   }
}

class SubType extends SuperType{
   constructor(name,age){
      // 继承属性
      super(name);
      this.age = age;
   }
   sayAge(){
      console.log(this.age); 
   }
}