Kalkulator

import java.awt.*;
import javax.swing.*;
public class Kalkulator extends JFrame {
    public Kalkulator() {
        JTextField wynik = new JTextField("0.0");
        wynik.setEditable(false);

        JButton b1 = new JButton("1");
        JButton b2 = new JButton("2");
        JButton b3 = new JButton("3");
        JButton b4 = new JButton("4");
        JButton b5 = new JButton("5");
        JButton b6 = new JButton("6");
        JButton b7 = new JButton("7");
        JButton b8 = new JButton("8");
        JButton b9 = new JButton("9");
        JButton b10 = new JButton("0");
        JButton b11 = new JButton(".");
        JButton b12 = new JButton("+");
        JButton b13 = new JButton("-");
        JButton b14 = new JButton("*");
        JButton b15 = new JButton("/");
        JButton b16 = new JButton("=");
        JButton b17 = new JButton("MC");
        JButton b18 = new JButton("MR");
        JButton b19 = new JButton("MS");
        JButton b20 = new JButton("M+");

        JPanel container = new JPanel();
        JPanel display = new JPanel();
        JPanel flow = new JPanel();
        JPanel memory = new JPanel();
        JPanel digits = new JPanel();

        display.add(wynik);

        memory.add(b17);
        digits.add(b7);
        digits.add(b8);
        digits.add(b9);
        digits.add(b12);

        memory.add(b18);
        digits.add(b4);
        digits.add(b5);
        digits.add(b6);
        digits.add(b13);

        memory.add(b19);
        digits.add(b1);
        digits.add(b2);
        digits.add(b3);
        digits.add(b14);

        memory.add(b20);
        digits.add(b10);
        digits.add(b11);
        digits.add(b16);
        digits.add(b15);

        flow.add(memory);
        flow.add(digits);
        container.add(display);
        container.add(flow);

        add(container);

        container.setLayout(new GridLayout(0,1));
        flow.setLayout(new FlowLayout());
        memory.setLayout(new GridLayout(0,1,0,5));
        display.setLayout(new GridLayout(0,1));
        digits.setLayout(new GridLayout(0,4,3,3));

        setTitle("Kalkulator");
        setSize(500, 500);
        setVisible(true);
    }
    public static void main(String[] args) {
        Kalkulator mojKalkulator = new Kalkulator();
    }
}