e3_11.java

来自「java 初学者学习实例」· Java 代码 · 共 64 行

import java.applet.*;
import java.awt.*;
interface Computable
{
   final int MAX = 100;
   void speak (String s);
   int f(int x);
   float g(float x,float y);
}
class China implements Computable
{
   int xuehao;
   public int f(int x)
   {
      int sum = 0;
	  for(int i =1;i <=x;i++)
	  {
	     sum = sum + i;
	  }
	  return sum;
   }
   public float g(float x,float y)
   {
      return 6;//至少一条语句
   }
   public void speak(String s)
   {
   }//必须有方法体
}
//
class Japan implements Computable
{
   int xuehao;
   public int f(int x)
   {
     
	  return 68;
   }
   public float g(float x,float y)
   {
      return x+y;//至少一条语句
   }
   public void speak(String s)
   {
   }//空
}


public class E3_11 extends Applet
{
	China Li;
	Japan Nip;
	public void init()
	{
		Li=new China();Nip = new Japan();
		Li.xuehao = 991898;
		Nip.xuehao = 991897;
	}
	public void paint(Graphics g)
	{
	    g.drawString("xuehao: "+Li.xuehao+Li.MAX+" 从1到100求和 "+Li.f(100),10,20);
	    g.drawString("xuehao: "+Nip.xuehao+Nip.MAX+" 求和 "+Nip.g(2.0f,3.0f),10,40);
	}
}