checkboxawt.java

import java.awt.*;
import java.awt.event.*;

class myframe extends Frame implements ItemListener
{
    Label l;
    Checkbox c1,c2,c3;
// note: when set of checkboxes are placed in a grp they become radio button 
    public myframe()
    {
        super("checkbox demo");
        l= new Label("Nothing is selected");
        c1 = new Checkbox("JAVA");
        c2 = new Checkbox("C++");
        c3 = new Checkbox("C");

        c1.addItemListener(this);
        c2.addItemListener(this);
        c3.addItemListener(this);
        
        setLayout(new FlowLayout());
        
        add(l);
        add(c1);
        add(c2);
        add(c3);
    }

    public void itemStateChanged(ItemEvent e) {
        String str="";
        if(c1.getState())
            str = str+"  "+c1.getLabel();
        if(c2.getState())
            str = str+"  "+c2.getLabel();
        if(c3.getState())
            str = str+"  "+c3.getLabel();
        
        if(str.isEmpty())
           str="nothing is selected";

       l.setText(str);

    }
    
}
public class checkboxawt {
   public static void main(String arg[])
   {
      myframe f = new myframe();
      f.setSize(500,500);
      f.setVisible(true);
   } 
}