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Shape类:定义一个Shape类(draw()方法),子类Circle、Rectangle重写draw()。编写一个方法,调用其draw()方法,并在main中测试。
Vehicle类:定义一个抽象父类vehicle,包含抽象方法run()。实现Car、Bicycle、Truck三个子类。在主方中创建Vehicle数组,存放不同车辆,遍历调用run()。
Al协助说明:
1.怎么在main方法中创建数组?
A:1. 创建父类类型数组,长度为3
Vehicle[] vehicles = new Vehicle[3];
// 2. 放入 3 个具体交通工具对象(多态)
vehicles[0] = new Car();
vehicles[1] = new Bicycle();
vehicles[2] = new Truck();
2.如何遍历数组?
写法 1:普通 for 循环
for (int i = 0; i < vehicles.length; i++) {
vehicles[i].run(); // 自动调用子类重写的run()
}
写法 2:增强 for 循环
for (Vehicle v : vehicles) {
v.run(); // 直接遍历每个元素,无需下标
}