实验四 java继承与多态.doc

//实验四第一题源程序
classPoint2D
{
intx;
inty;
Point2D(intx,inty)
{
this.x=x;
this.y=y;
}
voidoffset(inta,intb)
{
x=x+a;
y=y+b;
System.out.println("平移后："+x+","+y);
}
voidprint(Point2Dp2d1,Point2Dp2d2)
{
doubleL1=Math.sqrt(Math.pow((p2d1.x-p2d2.x),2)+Math.pow((p2d1.y-p2d2.y),2));
System.out.println("L1="+L1);
}
}
classPoint3DextendsPoint2D
{
intz;
Point3D(intx,inty,intz)
{
super(x,y);
this.z=z;
}
Point3D(Point2Dp,intz)
{
super(p.x,p.y);
this.z=z;
}
voidoffset(inta,intb,intc)
{
x=x+a;
y=y+b;
z=z+c;
}
voidprint(Point3Dp3d1,Point3Dp3d2)
{
doubleL2=Math.sqrt(Math.pow((p3d1.x-p3d2.x),2)+Math.pow((p3d1.y-p3d2.y),2)+Math.pow((p3d1.z-p3d2.z),2));
System.out.println("L2="+L2);
}
publicstaticvoidmain(String[]args)
{
Point2Dp2d1=newPoint2D(2,3);
Point2Dp2d2=newPoint2D(4,5);
Point3Dp3d1=newPoint3D(2,3,4);
Point3Dp3d2=newPoint3D(4,5,6);
p2d1.print(p2d1,p2d2);
p3d1.print(p3d1,p3d2);
}
}

//实验四第二题源程序
abstractclassShape
{
abstractpublicvoidshowArea();
}
interfaceDiagArea
{
doublegetDiagonal();
doublegetArea();
}
classRectangleimplementsDiagArea
{
intw,h;
Rectangle(inti,intj)
{
w=i;
h=j;
}
publicvoidshowArea()
{
ints1=w*h;
System.out.println("s矩形="+s1);
}
publicdoublegetDiagonal()
{
doubleL=Math.sqrt(w*w+h*h);
System.out.println("对角线长="+L);
returnL;
}
publicdoublegetArea()
{
doubles=w*h;
System.out.println("S矩形面积="+s);
returns;
}
}
classSquareextendsRectangle
{intx;
Square(intx)
{
super(x,x);//此处修改前为x=i;
this.x=x;
}
publicvoidshowArea()
{
ints2=x*x;
System.out.println("s正方形="+s2);
}
}
classCircle
{
intr;
Circle(inti)
{
r=i;
}
publicvoidshowArea()
{
doubles3=Math.PI*(r*r);
System.out.println("s圆="+s3);
}
voidshow()
{
System.out.println("圆的半径="+r);
}
}
classAreas
{
publicstaticvoidmain(String[]args)
{
RectangleRe=newRectangle(2,3);
SquareSq=newSquare(4);
CircleCi=newCircle(5);
Re.showArea();
System.out.println("实现接口运算");
doubleL=Re.getDiagonal();
doubleS=Re.getArea();
System.out.println("\n");
Sq.showArea();
System.out.println("实现接口运算"