deskclass.java

我在学习JAVA的讲义

import java.awt.Graphics;

//定义一个Desk类
class Desk
{   public String color;
    public int length;
    public int width;
    public int height;

    //计算桌子体积的方法
    int volume( )
    {   return length*width*height;
    }

    //显示桌子信息的方法
    void deskMessage(Graphics g,int x,int y)
    {   g.drawString("桌子的颜色:"+color,x,y);
        g.drawString("桌子的长度:"+length,x,y+10);
        g.drawString("桌子的宽度:"+width,x,y+20);
        g.drawString("桌子的高度:"+height,x,y+30);
    }
}

//该类声明一个Desk对象
public class DeskClass extends java.applet.Applet
{   public void paint(Graphics g)
    {   Desk myDesk=new Desk( );
        int myDeskVolume,volume;
        //给myDesk的实例变量赋值
        myDesk.color="Red";
        myDesk.length=23;
        myDesk.width=34;
        myDesk.height=25;
        //计算桌子的体积
        myDeskVolume=myDesk.volume();
        volume=myDesk.length*myDesk.width*myDesk.height;
        g.drawString("体积是:"+myDeskVolume,20,20);
        g.drawString("体积是:"+volume,20,40);
        myDesk.deskMessage(g,160,20);
    }
}