Person.java ~~~ package obj.a3; public class Person { String name; String sex; int age=23; /** * 无参无返回 */ public void eat(){ System.out.println("正在吃饭"); } /** * 有参无返回 */ public void sleep(String a){ System.out.println("小明正在"+a+"睡觉"); } /** * 有参有返回 */ public int getAge(int a){ return a; } } ~~~ Test.java ~~~ package obj.a3; public class Test { public static void main(String[] args){ Person p =new Person(); p.sleep("床上"); int age=p.getAge(18); System.out.println("年龄"+age); } } ~~~