day09-多态的好处

day10/src/com/inmind/duotai08/test/Assistant.java

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+package com.inmind.duotai08.test;
+
+public class Assistant extends Employee{
+    @Override
+    public void work() {
+        System.out.println("辅导员在辅导学生");
+    }
+}

day10/src/com/inmind/duotai08/test/Demo09.java

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+package com.inmind.duotai08.test;
+/*
+多态的核心好处可以概括为：**“以不变应万变”**—— 通过接口或者父类，应对具体实现的变化。
+它让代码更简洁、更灵活、更易于扩展，是构建大型、可维护系统的关键技术。
+ */
+public class Demo09 {
+    public static void main(String[] args) {
+        //没有多态的代码编写
+        //创建出每个子类对象，固定地执行一段功能代码，调用子类的work
+        Teacher teacher = new Teacher();
+
+        Assistant assistant = new Assistant();
+
+        //以上代码没有多态，所以有50个子类，重复的代码就要编写或封装50次，太繁琐
+        //多态写法
+        Employee e1 = new Teacher();
+        Employee e2 = new Assistant();
+        dTWork(e1);
+        dTWork(e2);
+        dTWork(teacher);
+        dTWork(assistant);
+    }
+
+    //定义一个父类类型接收子类对象，多态的写法
+    private static void dTWork(Employee employee) {
+        System.out.println("hello");
+        System.out.println("world");
+        employee.work();
+    }
+
+    //定义一个重复调用的普通写法
+    /*private static void dWork1(Assistant assistant) {
+        System.out.println("hello");
+        System.out.println("world");
+        assistant.work();
+    }
+
+    private static void dWork(Teacher teacher) {
+        System.out.println("hello");
+        System.out.println("world");
+        teacher.work();
+    }*/
+
+
+
+}

day10/src/com/inmind/duotai08/test/Employee.java

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+package com.inmind.duotai08.test;
+
+public abstract class Employee {
+    String name;
+    int age;
+
+    public abstract void work();//强制子类必须实现重写该方法
+}

day10/src/com/inmind/duotai08/test/Teacher.java

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+package com.inmind.duotai08.test;
+
+public class Teacher extends Employee{
+    @Override
+    public void work() {
+        System.out.println("老师在上课");
+    }
+}