public void startApp() { Form form = new Form("Calculator");

siResult.setText("Result: " + res); tfNumber1.setString(""); tfNumber2.setString(""); tfNumber1.setVisible(true); tfNumber2.setVisible(false); isNumber1 = true; } else if (c == cmdExit) { destroyApp(true); } } });

display.setCurrent(form); }

public CalculatorMIDlet() { display = Display.getDisplay(this); }

tfNumber2 = new TextField("Number 2: ", "", 10, TextField.NUMERIC); tfNumber2.setVisible(false); form.append(tfNumber2);

public class CalculatorMIDlet extends MIDlet { private Display display; private TextField tfNumber1, tfNumber2, tfResult; private String num1 = "", num2 = "", operator = ""; private boolean isNumber1 = true;

if (operator.equals("+")) { res = n1 + n2; } else if (operator.equals("-")) { res = n1 - n2; } else if (operator.equals("*")) { res = n1 * n2; } else if (operator.equals("/")) { if (n2 != 0) { res = n1 / n2; } else { siResult.setText("Result: Error"); return; } }