SE-1011 Software Development 1
Lab 3: Temperature Converter

Outcomes

• Continue to develop proficiency with the Java language
• Create Java mathematical expressions using arithmetic operators and assignment
• Declare and use numeric variables using appropriate naming conventions and datatypes

In this lab, you will write a Java program that uses a dialog box to prompt the user for a temperature in degrees Fahrenheit (for example -10.25), computes the equivalent temperature in degrees Celsius, and outputs the result in a dialog box.

Don't overwrite your files from last week's assignment. Create a new Eclipse project (in the same workspace), using the Eclipse Project Wizard (like last week). This time, name your package msoe.se1011.<yourname>, and name the class TemperatureConverter. Be sure to have the wizard automatically add a main method and comments that you can add to later.

You must write the Java instructions that implement the algorithm yourself. You can refer back to the program from the previous lab, but be careful about simply copying parts of that program. You should enter each instruction of this program manually in order to get a "feel" for the syntax and structure of the statements.

Detailed requirements

Study these requirements before implementing your program. This assignment requires you to construct a flowchart before you begin coding.

• After prompting the user for input, your program must convert the received String to a numeric value.

  There are various ways user may have entered an invalid temperature (e.g. "a", or "-10_3" ), pressing "OK" with no input, or pressing Cancel (with or without input). Handling any of these conditions is beyond what you learned so far in this course, so you don't have to worry about it for now (maybe next week, though). It is OK if your program crashes in any of these cases.

• The mathematical formula for converting from degrees F to degrees C is given by

  

  where T_c is the computed temperature in degrees Celsius
  T_F is the input temperature in degrees Fahrenheit

  • You must translate the math formula above into an equivalent Java formulation, using the correct operators for grouping, multiplication, and division. Your formula must make explicit use of Java's assignment, multiplication, subtraction, and division operators.
  • You must create your own Java variables with meaningful names (and appropriate datatypes) to represent the values for the temperatures.
     

Test your program and make certain that it works correctly, both for valid and invalid inputs.

•     32 F is 0 C
•     212 F is 100 C
•     75 F is 23.889 C (to three decimal places of precision)
•     -40 F is also -40 C

Test for the 4 cases above, as well as for 4 other values (pick some reasonable values). Add comments to the bottom of your java file, where you include these 8 results. Make sure your results are understandable to me, the reader.

Comment your program appropriately, as discussed in lecture. Be sure to add your name, date, and Lab assignment information at the top of the java file as a comment.

Remember: While you may discuss the concepts with your classmates, you must write your own program. You may not copy or borrow code from your classmates. If you do, you will be given a grade of 0 and reported to the office academic affairs.

Lab Submission (due by end of lab)

Submit your assignment following these instructions:

1. Hand in your flowchart to your instructor.
2. Upload your .java file through WebCT (assignment "Lab 3: Temperature Converter").

Your grade will be based on the following criteria:

• Meeting requirements; your program must compile and run. If you have trouble, you must come to see me. If you don't and you submit a program that does not compile or produce meaningful results will receive a grade of no higher than 50, even after reworking your program.
• Technical quality of both your program and your lab report. For the program, technical quality consists of formatting, commenting, and following coding style guidelines we discussed in lectures.
• Spelling and grammar (Eclipse even has a built-in spell checker - make use of it!)
• Timeliness of submission as stated in the course policies.