Калькулятор, третье занятие

String name = button.getText();

        if (name == "Выход") {
            System.exit(0);
        } else if (name == "C") {
            result.setText("");
            first = second = 0;
        } else if (name == "=") {
            second = Integer.parseInt(result.getText());

            if (operation == 1)
                result.setText("" + (first + second));
            else if (operation == 2)
                result.setText("" + (first - second));
            else if (operation == 3)
                result.setText("" + (first * second));
            else if (operation == 4)
                result.setText("" + (first / second));
        } else if (name == "+") {
            operation = 1;
            first = Double.parseDouble(result.getText());
            result.setText("");
        } else if (name == "=") {
            operation = 2;
            first = Double.parseDouble(result.getText());
            result.setText("");
        } else if (name == "*") {
            operation = 3;
            first = Double.parseDouble(result.getText());
            result.setText("");
        } else if (name == "/") {
            operation = 4;
            first = Double.parseDouble(result.getText());
            result.setText("");
        } else {
            result.setText("" + result.getText() + name);
        }