JS继承对比 #20
Description
JS继承
JS的继承方式有很多种，最理想的继承方式是寄生组合式继承。
组合继承
function Person(name) {
this.name = name;
}
Person.prototype.sayHi = function() {
console.log(this.name + '-' + '-hi');
}
function SubPerson(name, age) {
Person.call(this, name);
this.age = age;
}
SubPerson.prototype = new Person();
SubPerson.prototype.constrcutor = SubPerson;
var sp = new SubPerson('clearives', 18);
console.log(sp);
sp.sayHi();组合继承（构造函数和原型的组合）会调用两次父类构造函数的代码
寄生组合式继承
function inheritPrototype(SubPerson, Person){
var protoType = Object.create(Person.prototype);
protoType.constructor = SubPerson;
SubPerson.prototype = protoType;
}
function Person(name) {
this.name = name;
}
Person.prototype.sayHi = function() {
console.log(this.name + '-' + '-hi')
}
function SubPerson(name, age) {
Person.call(this, name);
this.age = age;
}
inheritPrototype(SubPerson, Person);
var sp = new SubPerson('clearives', 18);
console.log(sp);
sp.sayHi();这样避免了调用两次父类的构造函数，为其创建多余的属性。
其它
function object(o) {
function F(){}
F.prototype = o;
return new F();
}
// 这个函数其实就是Object.create的简单实现