CSC02- Lab 09 Solved

Objective: This assignment will give you practice with action event handling.

The programming assignment:

In this assignment you are to add functionality to the calculator created in lab 08. You don’t have to make the calculator a full function calculator. You only need to make buttons 0 ~ 9, +, -, *, / and = work.

 

Some programming hints:

 

1. Implement an action listener.

 

public void actionPerformed(ActionEvent e) {           for (int i=0; i<=9; ++i) {              if (e.getSource() == digitButton[i]) {

                                                if (newNumber) {

display digit in tf;

newNUmber = false;

                                                } else append digit in tf;

return;

                                    }

                        }

            if (e.getSource() == addButton ){                opnd1 = Double.parseDouble(tf.getText());

                                    newNumber = true;

                                    operator = ‘+’; return;

                        }

            if (e.getSource() == eqButton) {                 opnd2 = Double.parseDouble(tf.getText());    switch (operator) {                                   case ‘/’: res = opnd1 / opnd2; break;                          case ‘*’: res = opnd1 * opnd2; break;                                   case ‘-‘: res = opnd1 - opnd2; break;

                                                case ‘+’: res = opnd1 + opnd2; break;

                                    }

                        display(""+res);              newNumber = true;            return;

                        }

}

 

2. Register the action listener with all buttons.