JAVA¼ÆËã»ú´úÂë

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
public class j5_13 extends Applet implements ActionListener
{
  Panel p=new Panel();//н¨²¼¾Ö
  Label welcome,la1,li1,la2,li2,lresult;//Ìáʾ±êÇ©,·ûºÅ±êÇ©ÒÔ¼°¼ÆËã½á¹ûµÄ±êÇ©
  TextField ta,tb,tc,td;//³öÈëÊý¾Ý¿ò
  CheckboxGroup select;//µ¥Å¥Ñ¡Ôñ
  Checkbox ad,mi,mu,di;//·Ö±ð¶ÔÓ¦¼Ó¼õ³Ë³ý
  Button be,br;//¶ÔÓ¦¼ÆËã°´Å¥ºÍÖØÖð´Å¥
  public void init()
  {
       select=new CheckboxGroup();
       add(welcome=new Label("ÇëÊäÈëÒª¼ÆËãµÄ¸´Êý:"));
       add(ta=new TextField(4));
       add(la1=new Label("+"));
       add(tb=new TextField(4));
       add(li1=new Label("i"));
       add(ad=new Checkbox("¼Ó",true,select));
       add(mi=new Checkbox("¼õ",false,select));
       add(mu=new Checkbox("³Ë",false,select));
       add(di=new Checkbox("³ý",false,select));
       add(tc=new TextField(4));
       add(la2=new Label("+"));
       add(td=new TextField(4));
       add(li2=new Label("i"));
       add(be=new Button("¼ÆËã"));
       add(br=new Button("ÖØÖÃ"));
       add(lresult=new Label("½á¹û:              "));
       be.addActionListener(this);
       br.addActionListener(this);
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