CSCI 51, Spring 2009

Program 2: GUI Calculator

75 points

Assigned: Tuesday, February 3
Due: Tuesday, February 10 at 11:59PM

Description

Write a GUI-based program that mimics a calculator. The program should take as input two floating-point numbers
and the operation to be performed. It should then output the numbers, the operator, and the result (formatted to two
decimal places).

The user input should be in the format operand1 operator operand2, where the operands and the operator are
separated by spaces. For example, to add 2 and 3, the user should enter 2 + 3 in the text field of the dialog box.

You should support the following operations: addition (+), subtraction (-), multiplication (*), division (/), exponent (^),
and the mod (%) operator.

Note: operand1 ^ operand2 means that operand1 should be raised to the operand2(th) power.

Special cases to handle:

For division, if the denominator is zero, print an appropriate message.

If the user enters an invalid operator (i.e., anything not +, -, *, /, ^), print an appropriate message.

You are not responsible for making sure that the user enters numbers, instead of letters, for the operands. This would cause a "NumberFormatException" when trying to tokenize the input string.

Here's an example run:

What to Turn in

Your Calculator.java file, as an attachment to the asssignment in Sakai assignments.

What to Do

Name your Java source file Calculator.java and your class Calculator.

Requirements

When I run/examine your program, it must satisfy the following requirements. The maximum point value for each is shown in brackets.

[5] Your class, Java source file, and Jar file must be appropriately named (as specified above).
[10] You must use the JOptionPane class to create dialog boxes for user input and output. Your user input dialog box should contain instructions for using the program, including a list of the supported operations.
[10] You must display the correct result of the calculation to the user.
[10] If the user attempts to divide by 0, you must print a message to that effect (e.g., "division by 0 not allowed").
[10] If the user enters an invalid operator, you must print a message to that effect (e.g., "operation not supported").
[10] You must format the result of the calculation to two decimal places.
[10] You must use meaningful variable names, which conform to the style guidelines and Java naming convention discussed in class.
[10] You must comment your code, including block-like multi-line comments and single-line comments where appropriate. In addition, your code must be neatly and clearly formatted using appropriate "white space."