objectconvert.java

Java讲义与实例

class SuperClass{
	private int x=100;
	public int getx(){
		return x;
		}
	}
class Subbie extends SuperClass{
	private int y=200;
	public int gety(){
	    return y;	
		}
	}
public class ObjectConvert{
	public static void main(String arg[]){
		SuperClass superA=new SuperClass(),superB;
		Subbie subA=new Subbie(),subB;
		(new ObjectConvert()).useSubAsSuper(subA);
		superB=subA;
		System.out.println("superA.getx():"+superB.getx());
		subB=(Subbie)superB;
	    System.out.println(subB.getx()+"  "+subB.gety());
		}
		public void useSubAsSuper(SuperClass x){
			System.out.println(x.getx()+"!!!!!!");
			}
	}