classinheritance.java

我在学习JAVA的讲义

class A
{   int a1=1;
    public int a2=2;
    protected int a3=3;
    private int a4=4;
    int geta4( ){return a4;}
}
class B extends A
{   int b=5;
    int sum( ){return a1+a2+a3+geta4( )+b;}
}

class ClassInheritance
{   public static void main(String args[ ])
    {    A aa=new A( );
        System.out.println("A:"+aa.a1+"\t"+aa.a2+"\t"+aa.a3+"\t"+aa.geta4( ));
        B bb=new B( );
        System.out.println("B:"+bb.a1+"\t"+bb.a2+"\t"+bb.a3+"\t"+bb.geta4( )+
	                   "\t"+bb.b+"\t"+bb.sum( ));
    }
}