JavaSE-面向对象(方法重写)

package Demo1;
import java.util.Arrays;
public class Demo011 {
    public static void main(String[] args) {
        Demo011 D11=new Demo011();
        D11.demo(12,232,43,3);		//4个实际参数，则调用第三个demo方法
    }
    public void demo(int a,int b){
        System.out.println(a+b);
    }
    public void demo(int a,int b,int c){
        System.out.println(a+b+c);
    }
    public void demo(int...ints){
        System.out.println(Arrays.toString(ints));
    }
}

package Demo1;
public class Demo012 {
    public static void main(String[] args) {
            B b =new B();
            b.demo();
    }
}
class A{
    public static void demo(){
        System.out.println("Ademo");
    }
}
class B extends A{
    public static void demo(){
        System.out.println("Bdemo");
    }
}

    public static void main(String[] args) {
    //方法的调用只和数据类型有关
            B b =new B();		//调用的是B类的静态方法
            b.demo();
            //父类的引用指向子类
            A a = new A();		//调用的是A类的静态方法
            a.demo();
    }

class A{
    public  void demo(){
        System.out.println("Ademo");
    }
}
class B  extends A{
    @Override	//注解，有功能的注释
    public void demo() {
        super.demo();		//默认调用父类的demo()方法
    }
}

class A{
    public  void demo(){
        System.out.println("Ademo");
    }
}
class B  extends A{
    @Override
    public void demo() {
        //super.demo(); 默认调用父类的demo()方法输出Ademo
        System.out.println("Bdemo");
    }
}

package Demo3;
public class demo005 {
    public static void main(String[] args) {
            DemoB DB =new DemoB();
            DB.demo();		//调用子类的demo
            DemoA DA=new DemoA();	//调用父类的demo
            DA.demo();
    }
}
class DemoA{
    public void demo(){
        System.out.println("demoA");
    }
}
class DemoB extends DemoA{		//继承
    @Override
    public void demo(){
        System.out.println("demoB");
    }
}

package Demo3;
public class demo005 {
    public static void main(String[] args) {
            DemoB DB =new DemoB();
            DB.demo();
            DemoA DA=new DemoA();
            DA.demo();
    }
}
class DemoA{
    public void demo(){
        System.out.println("demoA");
    }
}
class DemoB{		//A与B没有继承关系
    public void demo(){
        System.out.println("demoB");
    }
}