JS继承与工厂构造及原型设计模式详解

function SuperType(name){
     this.name = name;
     this.colors = ["red", "blue", "green"];
}
function SubType(name, age){
     SuperType.call(this, name) // 构造函数继承 （两次调用父类构造函数）
     this.age = age;
}
SuperType.prototype.sayName = function() {
     console.log(this.name);
}
SubType.prototype = new SuperType() // 原型链继承 （一次调用父类构造函数）
SubType.prototype.sayAge = function() {
	 console.log(this.age);
}
let s1 = new SubType("Nicholas", 29)
let s2= new SubType("Greg", 27)
s1.colors.push("yellow")
console.log(s1.colors) // ['red', 'blue', 'green', 'yellow']
console.log(s2.colors) // ['red', 'blue', 'green']
s1.sayName() // Nicholas
s2.sayName() // Greg
s1.sayAge() // 29
s2.sayAge() // 27

function createAnother(original){
     let clone = Object(original); // 通过调用函数创建一个新对象
     clone.sayHi = function() { // 以某种方式增强这个对象
         console.log("hi");
     };
     return clone; // 返回这个对象
}

function inheritPrototype(subType, superType) {
     let prototype = Object(superType.prototype); // 创建对象
     prototype.constructor = subType; // 增强对象
     subType.prototype = prototype; // 赋值对象
}
function SuperType(name) {
     this.name = name;
     this.colors = ["red", "blue", "green"];
}
function SubType(name, age) {
     SuperType.call(this, name); // 构造函数继承（只调了一次）
     this.age = age;
}
SuperType.prototype.sayName = function() {
     console.log(this.name);
};
inheritPrototype(SubType, SuperType); // 寄生继承
SubType.prototype.sayAge = function() {
     console.log(this.age);
};
let s1 = new SubType("Nicholas", 29)
let s2= new SubType("Greg", 27)
s1.colors.push("yellow")
console.log(s1.colors) // ['red', 'blue', 'green', 'yellow']
console.log(s2.colors) // ['red', 'blue', 'green']
s1.sayName() // Nicholas
s2.sayName() // Greg
s1.sayAge() // 29
s2.sayAge() // 27

SuperType.prototype.constructor=== SubType // true

SubType === SubType.prototype.constructor // true
SuperType.prototype.constructor === SubType.prototype.constructor // true