看了些其他人写的，还有画的图，感觉还是无法直观理解，还是直接看输出吧，反正就两个属性prototype跟__proto__
function male (name, age) {
this.name = name;
this.age = age;
}
male.prototype.sex = 'male';
male.prototype.getValue = function () {
console.log('getValue:' + this.sex)
}
console.log('1 male.__proto__(): ' + male.__proto__()); // undefined 不存在
console.log('2 male.__proto__:' + male.__proto__); // function () { [native code] }
console.log('2.1 constructor:' + male.constructor) // 同上
var person1 = new male('li', 13);
// person1.__proto__.sex = 'sprot';
var person2 = new male('wang', 32);
console.log('3 person1: ' + JSON.stringify( person1)); // {"name":"li","age":13}
console.log('4 person2: ' + person2); // [object Object]
console.log('5 person1.prototype: ' + person1.prototype); // undefined
// console.log('6 person1.__proto__(): ' + person1.__proto__()); // is not a function
console.log('7.1 person1.sex:' + person1.sex);
console.log('7 person1.__proto__: ' + person1.__proto__); // [object Object] {'sex': 'male'} 指向下行中的male.prototype
console.log('8 male.prototype: ' + JSON.stringify(male.prototype)); // {'sex': 'male'}
// 继承另一种写法
function person (arg1, arg2) {
male.call(this, arg1, arg2)
}
person.prototype = new male();
const person3 = new person('mac', '11');
person3.getValue()
console.log('9 person3 instanceof male: ' + (person3 instanceof male));
console.log('9.1 person1 instanceof male:' + (person1 instanceof male));
es6中的继承用起来更爽一些，像极了java,但底层还是基于原型链实现的。
class Parents {
constructor (name, age) {
this.name = name;
this.age = age;
}
show () {
console.log('I am ' + this.name + ',' + this.age + ' years old.');
}
};
class Child extends Parents {
// 构造函数重写
constructor (name, age, sex) {
super(name, age);
this.sex = sex;
}
// 还可以重写show
show () {
console.log(this.name + '==' + this.age + '==' + this.sex);
}
};
class Child2 extends Parents {}
let child = new Child('mac', 18, 'male');
child.show();
let child2 = new Child2('child', 7);
child2.show();
仅作为个人学习、阅读笔记，如有不足之处请指教，如有侵权请联系本人即删除
