代码语言：javascript复制
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script type="text/javascript">
function Person(myName, myAge) {
// let per = new Object();
// let this = per;
// this = stu;
this.name = myName; // stu.name = myName;
this.age = myAge; // stu.age = myAge;
// return this;
}
Person.prototype.say = function () {
console.log(this.name, this.age);
}
function Student(myName, myAge, myScore) {
Person.call(this, myName, myAge);
this.score = myScore;
this.study = function () {
console.log("day day up");
}
}
/*
弊端:
1.由于修改了Person原型对象的constructor属性, 所以破坏了Person的三角恋关系
2.由于Person和Student的原型对象是同一个, 所以给Student的元素添加方法, Person也会新增方法
*/
// Student.prototype = Person.prototype;
Student.prototype = new Person();//
Student.prototype.constructor = Student;
Student.prototype.run = function(){
console.log("run");
}
let per = new Person();
per.run();
/*
1.js中继承的终极方法
1.1在子类的构造函数中通过call借助父类的构造函数
1.2将子类的原型对象修改为父类的实例对象
*/
// let stu = new Student("ww", 19, 99);
// console.log(stu.score);
// stu.say();
// stu.study();
</script>
</body>
</html>
