属性上的自定义属性 - 获取属性的类型和值

var obj = {
  name: 'John',
  age: 25
};

console.log(typeof obj.name); // 输出 "string"
console.log(typeof obj.age); // 输出 "number"

import java.lang.reflect.Field;

public class MyClass {
  private String name = "John";
  private int age = 25;

  public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
    MyClass obj = new MyClass();

    Field nameField = obj.getClass().getDeclaredField("name");
    nameField.setAccessible(true);
    String nameValue = (String) nameField.get(obj);
    System.out.println(nameValue); // 输出 "John"

    Field ageField = obj.getClass().getDeclaredField("age");
    ageField.setAccessible(true);
    int ageValue = ageField.getInt(obj);
    System.out.println(ageValue); // 输出 25
  }
}