Program kalkulator sederhana

KalkulatorSederhana.java

package pertemuan7;

import javax.swing.JOptionPane;

/**
 *
 * @author petanikode
 */
public class KalkulatorSederhana {
    
    public static void main(String[] args) {
        
        boolean keluar = false;
        float hasil, a, b;
        
        while (keluar == false){
            
            // tampilkan menu
            String pilihan = JOptionPane.showInputDialog("Pilih Menu:\n"
                                                    + "1. Tambah\n"
                                                    + "2. Kurang\n"
                                                    + "3. Kali\n"
                                                    + "4. Bagi\n"
                                                    + "5. Keluar");

            
            switch(pilihan){
                case "1": 
                    a = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai a:"));
                    b = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai b:"));
                    hasil = a + b;
                    JOptionPane.showMessageDialog(null, "Hasil " + a +" + "+ b +" = " + hasil);
                    break;
                case "2":
                    a = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai a:"));
                    b = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai b:"));
                    hasil = a - b;
                    JOptionPane.showMessageDialog(null, "Hasil " + a +" - "+ b +" = " + hasil);
                    break;
                case "3":
                    a = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai a:"));
                    b = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai b:"));
                    hasil = a * b;
                    JOptionPane.showMessageDialog(null, "Hasil " + a +" * "+ b +" = " + hasil);
                    break;
                case "4":
                    a = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai a:"));
                    b = Integer.valueOf(JOptionPane.showInputDialog("Inputkan nilai b:"));
                    hasil = a / b;
                    JOptionPane.showMessageDialog(null, "Hasil " + a +" / "+ b +" = " + hasil);
                    break;
                case "5":
                    String yakin = JOptionPane.showInputDialog("Yakin ingin keluar?\n"
                            + "1. Ya\n"
                            + "2. Tidak");
                    
                    if (yakin.equals("1")) {
                        keluar = true;
                        System.exit(0);
                    }                  
                    break;
                default:
                    JOptionPane.showMessageDialog(null, "Pilihan '" + pilihan +"' tidak ada!");
                   
            }
            
            
        }
        
    }
    
}