3

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

class ElsoProgram extends Frame {
	ElsoProgram() {
		setTitle("Első program");

		Label ne = new Label("Ez egy felirat!");
		add(ne);

		setSize(400, 300);
		setVisible(true);
	}

	public static void main(String args[]) {
		new ElsoProgram();
	}

}


import java.awt.*;
import java.awt.event.*;
import static java.lang.Math.*;
import java.io.*;

public class MasdoikProgram extends Frame implements ActionListener
{
  Button gomb1, gomb2;
  TextField ne;

  public MasdoikProgram()	                    //konstruktor
  {
    setLayout(new FlowLayout());

	ne = new TextField("MasdoikProgram");
    gomb1 = new Button("MasodikProgramA");
	gomb2 = new Button("MasodikProgramB");

addWindowListener(new WindowAdapter()  {public void windowClosing(WindowEvent we){System.exit(0);}}  );

    gomb1.addActionListener(this);
    gomb2.addActionListener(this);
    add(ne);
    add(gomb1);
    add(gomb2);
    setTitle("MasodikProgram");
    setSize(300, 350);
    setVisible(true);
  }

  @Override
  public void actionPerformed(ActionEvent e)
  {
    String str = e.getActionCommand();	    // str a megnyomott gomb neve

    if (str=="MasodikProgramA") {
		ne.setText("Succes é!");
		//setTitle("" + sqrt(Double.parseDouble(ne.getText())));
		//ide johet barmi
	} //egyik vege

    if (str=="MasodikProgramB") {
		ne.setText("Siker é!");
	} //masik vege

	}

  public static void main(String args[]) {new MasdoikProgram();}

  } //MasdoikProgram vege










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

public class HarmadikProgram extends Frame implements ActionListener
{
	Button ne, ne2, ne3;

	public HarmadikProgram() {

		setLayout(new FlowLayout());

		ne = new Button("Egy");
		ne2 = new Button("Kettő");
		ne3 = new Button("Harom");

		addWindowListener(new WindowAdapter()  {public void windowClosing(WindowEvent we){System.exit(0);}}  );

		ne.addActionListener(this);
		ne2.addActionListener(this);
		ne3.addActionListener(this);

		add(ne);
		add(ne2);
		add(ne3);
		setTitle("HarmadikProgram");
		setSize(300, 350);
		setVisible(true);
		}

		@Override
		public void actionPerformed(ActionEvent e) {
			String str = e.getActionCommand();

			if(str=="Egy"){
				setTitle("Egy");
			}
			if(str=="Kettő") {
				setTitle("Kettő");
			};
			if(str=="Harom") {
				setTitle("Harom");
			}
		}

	public static void main(String args[])
	{
		new HarmadikProgram();
	}

}