Stuff

package hoofdstuk8;import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.*;/** * * @author Robin */public class Tafel extends JFrame implements ActionListener{    private JPanel paneel;    private JButton button;    private JTextField tekstveld;    private JButton[] knoppen;    private int waarde;    private JButton knop;    private JButton knop2;    private JLabel label;    private int randomwaarde;    private int resultaat;    private int geefi;    private int geefj;            public Tafel(){        GridLayout experiment = new GridLayout(10,10);        knop = new JButton("nieuw");        knop.addActionListener(this);        label = new JLabel();        tekstveld = new JTextField(300);        paneel = new JPanel();        knoppen = new JButton[101];        waarde = 0;                        paneel.add(knop, BorderLayout.PAGE_START);        paneel.add(tekstveld, BorderLayout.CENTER);        paneel.add(label, BorderLayout.PAGE_END);                knop2 = new JButton("1 x 1");        knop2.setEnabled(false);        knop2.setBackground(Color.WHITE);        paneel.add(knop2, BorderLayout.LINE_START);                        waarde =1;        for(int i = 1; i <= 10; i++) {            for(int j = 1; j <= 10; j++) {                if (waarde != 0){                knoppen[waarde] = new JButton(j+" x "+i);                knoppen[waarde].setEnabled(false);                knoppen[waarde].setBackground(Color.WHITE);                Component add = paneel.add(knoppen[waarde]);                waarde++;                }            }        }        int randomTafel = (int)(100*Math.random()) + 1;         knoppen[randomTafel].setBackground(Color.RED);        randomwaarde = randomTafel;                setContentPane(paneel);        setLayout(experiment);                    }        public void actionPerformed(ActionEvent e){        if (e.getSource() == knop){            waarde = 1;            for(int i = 1; i <= 10; i++) {                for(int j = 1; j <= 10; j++) {                    waarde++;                    if (waarde == randomwaarde){                        geefi = i;                        geefj = j;                    }                }            }            resultaat = geefi * geefj;              int invoer = Integer.parseInt(tekstveld.getText());            if (resultaat == invoer){               label.setText("goed");            }else{                label.setText("fout");            }                    }            }}