es5和es6 继承的不同
function Person(){};
function Student(){};
Student.prototype = new Person()
var stu = new Student()
console.log(stu.__proto__) // Person{}
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class Person{}
class Student extends Person{}
var stu = new Student()
console.log(stu.__proto__) //Student{}
es5和es6 的集成好像有点不一样
