package Test;
public class TestPolymorphicRequired {
public void shout() {
}
}
class Cat extends TestPolymorphicRequired{
@Override
public void shout() {
System.out.println("喵喵喵！");
}
}
class Dog extends TestPolymorphicRequired{
@Override
public void shout() {
System.out.println("汪汪汪！");
}
}
package Test;
public class TestPolymorphic {
public static void main(String[] args) {
// TODO 测试多态
TestPolymorphicRequired d = new Dog();
Dog dog = (Dog)d;
dog.shout();
}
}
多态的三个必要条件：
继承，重写，父类引用指向子类对象。