插入代码片段
function Student(name, age, gender) {
  this.name = name;
  this.age = age;
  this.gender = gender;
}
Student.prototype = {
  constructor: Student, // 手动将 constructor 指向正确的构造函数
  hobby: "study",
  sayHi: function() {
    console.log("hi");
  }
};

var s1 = new Student("wangwu", 18, "male");
console.log(Student.prototype.constructor === Student); // 结果为 true
copy

插入代码片段
function Student(name, age, gender) {
  this.name = name;
  this.age = age;
  this.gender = gender;
}
Student.prototype.sayHi = function() {
  console.log("hi");
};

var s1 = new Student("zhangsan", 18, "male");
s1.sayHi(); // 打印 hi
var s2 = new Student("lisi", 18, "male");
s2.sayHi(); // 打印 hi
copy