feat:w5

w5/Vehicle.java

@@ -0,0 +1,34 @@
+package Homework;
+
+abstract class Vehicle {
+    public abstract void run();
+}
+class Car extends Vehicle{
+    @Override
+    public void run(){
+        System.out.println("car is running");
+    }
+}
+class Bike extends Vehicle{
+    @Override
+    public void run(){
+        System.out.println("bike is running");
+    }
+}
+class Truck extends Vehicle{
+    @Override
+    public void run(){
+        System.out.println("truck is running");
+    }
+}
+class VehicleTest{
+    public static void main(String[]args){
+        Vehicle[] vehicles=new Vehicle[3];
+        vehicles[0]=new Car();
+        vehicles[1]=new Bike();
+        vehicles[2]=new Truck();
+        for(Vehicle i :vehicles){
+            i.run();
+        }
+    }
+}

w5/shape.java

@@ -0,0 +1,27 @@
+package Homework;
+
+public abstract class shape {
+    public abstract void draw();
+}
+class Circle extends shape{
+    @Override
+    public void draw(){
+        System.out.println("绘制一个圆形");
+    }
+
+}
+class Rectangle extends shape{
+    @Override
+    public void draw(){
+        System.out.println("绘制一个矩形");
+    }
+}
+class Main{
+    public static void drawShape(shape s){
+        s.draw();
+    }
+    public static void main(String[]args){
+        drawShape(new Circle());
+        drawShape(new Rectangle());
+    }
+}