COMP 110-001: Introduction to Programming, SSI'15

Homework 2: GUI Calculator

75 points

Assigned: Wednesday, May 20, 2015
Due: Tuesday, May 26, 2015 at 11:59pm (EDT)

Description

Write a GUI-based program that mimics a calculator. The program will take two floating-point numbers and the operation as input, and output the numbers, the operator, and the result (formatted to two decimal places) after performing the arithmetic operation.

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 (/), and mod (%).

Special cases to handle:

For division and mod, 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 parse the input string.

Here's an example:

Extra Credit:

Add the ^ operator to your code.
Note: operand1 ^ operand2 means that operand1 should be raised to the operand2(th) power. Assume that operand2 is an integer. There are Java packages that include the ^ operator, however you cannot use them for this extra credit. When testing the ^ operator use small numbers!

What to Do

Name your Java source file Calculator.java.
Include a text file named yourlastname_hw2.txt that has a short write-up of questions you had and/or problems you encountered while doing this assignment
Create a Jar file named yourlastname_hw2.jar using these instructions . Your jar file should include Calculator.java, Calculator.class, MANIFEST.MF, and yourlastname_hw2.txt
Submit your jar file via Sakai by Tuesday May 26, 2015 11:59pm

Requirements

When I examine your program, it must satisfy the following requirements. The maximum point value for each requirement 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. (See Lab 2) Your user input dialog box should contain instructions for using the program, including a list of the supported operations.
[10] You must correctly parse the user input String.
[10] You must display the correct result of the calculation to the user.
[5] If the user attempts to divide or mod by 0, you must print a message to the user(e.g., "division by 0 is not allowed").
[10] If the user enters an invalid operator, you must print a message to that effect (e.g., "operation is not supported").
[10] You must format the result of the calculation to two decimal places.
[5] You must use meaningful variable names, which conform to the style guidelines and Java naming convention discussed in class.
[5] 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".
[5] Extra Credit.

Notes:

If your program doesn't compile or run (i.e., with a syntax error), you will receive 0 credit for the listed items in bold. So you can only get at most 15 points, out of 75 points.
Remember that an implicit requirement for all assignments is that your code must include (at the top) the standard program header with pledge