js继承的6种方式详解

代码:
function SuperType() {
	this.property = true;
}
SuperType.prototype.getSuperValue = function() {
	return this.property;
};
function SubType() {
	this.subproperty = false;
}
// 继承SuperType
SubType.prototype = new SuperType();
SubType.prototype.getSubValue = function () { //注意 不能通过对象字面量的方式添加新方法，否则上一行无效
	return this.subproperty; 
};
let instance = new SubType();
console.log(instance.getSuperValue()); // true

function SuperType(name) {
 this.colors = ["red","blue","green"];
 this.name = name;
 }
function SubType(name) {
 SuperType.call(this,name);
}
let instance1 = new SuperType('小明')
let instance2 = new SuperType('小白')
instance1.colors .push('yellow')
console.log(instance1) //{name:"小明",colors:["red","blue","green","yellow"]...}
console.log(instance2) //{name:"小白",colors:["red","blue","green"]...}

//可以传递参数 也修复了引用的问题 可以继承多个构造函数属性（call多个）

function SuperType(name){
	this.name = name;
	this.colors = ["red","blue","green"];
}
SuperType.prototype.sayName = function() {
	console.log(this.name);
};
function SubType(name, age){
	// 继承属性 第二次调用
	SuperType.call(this, name);
	this.age = age;
}
// 继承方法 第一次调用
SubType.prototype = new SuperType();
SubType.prototype.sayAge = function() {
	console.log(this.age);
};
let instance1 = new SubType("Nicholas", 29);
instance1.colors.push("black");
console.log(instance1.colors); //["red,blue,green,black"]
instance1.sayName(); // "Nicholas";
instance1.sayAge(); // 29
let instance2 = new SubType("Greg", 27);
console.log(instance2.colors); // ["red,blue,green"]
instance2.sayName(); // "Greg";
instance2.sayAge(); // 27

//可以继承父类原型上的属性，可以传参，可复用。 每个新实例引入的构造函数属性是私有的 

function object(person) {
 function F() {}
 F.prototype = person
 return new F()
}

let person = {
 name:'小明',
 colors:['red','blue']
}

let person1 = object(person)
person1.colors.push('green')
let person2 = object(person)
person1.colors.push('yellow')
console.log(person) //['red','blue','green','yellow']

function object(person) {
 function F() {}
 F.prototype = person
 return new F()
}
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
}

//核心代码
function object(person) {
 function F(params) {}
 F.prototype = person
 return new F()
}
function inheritPrototype(SubType,SuperType) {
 let prototype = object(SuperType.prototype) //生成一个父类原型的副本

 //重写这个实例的constructor
 prototype.constructor = SubType

 //将这个对象副本赋值给 子类的原型
 SubType.prototype = prototype
}

function SuperType(name) {
	this.name = name;
	this.colors = ["red","blue","green"];
}
SuperType.prototype.sayName = function() {
	console.log(this.name);
};
function SubType(name, age) {
	SuperType.call(this, name);
	this.age = age;
}

//调用inheritPrototype函数给子类原型赋值,修复了组合继承的问题
inheritPrototype(SubType, SuperType);

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