// Java
public class Person {
    // 字段 (Field)
    private String name;
    private int age;

    // 构造器 (Constructor)
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // 方法 (Method)
    public void sayHello() {
        System.out.println("你好，我是" + name);
    }

    // Getter / Setter
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

// 使用
Person p = new Person("小明", 25);
p.sayHello();