Java 多态性

多态的理解与规则

代码理解：

Person类：

package Exer2; public class Person { int id = 1000; private int length; private int age; private String name; public Person() { } public Person(int id, int length, int age, String name) { super(); this.id = id; this.length = length; this.age = age; this.name = name; } public void eat() { System.out.println("人要吃饭"); } public void walk() { System.out.println("人会走路！"); } }

Man子类

package Exer2; public class Man extends Person{ boolean isHandsome; int id = 1001; public Man(boolean isHandsome) { super(); this.isHandsome = isHandsome; } public Man() { super(); } public void eat() { System.out.println("男人吃饭很多"); } public void earn() { System.out.println("男人负责赚钱"); } }

test测试

package Exer2; public class Test { public static void main(String[] args) { Person s1 = new Person(); s1.eat(); //多态 Person s2 = new Man(); s2.eat(); System.out.println(s2.id); // s2.earn(); } }