如何在JS中设置构造函数之外的属性，就像在Java中一样？

function Person(name, age) {
  this.name = name;
  this.age = age;
}

var person = new Person('Alice', 30);
person.gender = 'female'; // 在构造函数外部设置属性
console.log(person); // 输出: {name: "Alice", age: 30, gender: "female"}

function Person(name, age) {
  this.name = name;
  this.age = age;
}

Person.prototype.gender = 'unknown'; // 在原型上设置属性
var person = new Person('Bob', 25);
console.log(person.gender); // 输出: "unknown"

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }
}

let person = new Person('Charlie', 35);
person.gender = 'male'; // 在构造函数外部设置属性
console.log(person); // 输出: Person {name: "Charlie", age: 35, gender: "male"}

function Person(name, age) {
  this.name = name;
}
var person = new Person('David', 40);
person.name = 'Eve'; // 覆盖了构造函数内部的属性
console.log(person.name); // 输出: "Eve"

if (!person.hasOwnProperty('name')) {
  person.name = 'Eve';
}

Person.prototype.gender = 'unknown';
var person1 = new Person('Frank', 45);
var person2 = new Person('Grace', 50);
person1.gender = 'male';
console.log(person2.gender); // 输出: "male"，因为原型链被污染

function Person(name, age) {
  this.name = name;
  this.age = age;
  this.gender = 'unknown'; // 在构造函数内部设置默认值
}