CS 134 Lab Style Guide
The way you present your program is just as important as having a
correct program. While having good comments or good variable names
will not affect the correctness of your program, it will make it
easier to read your program. It is important that others be able to
understand your code so that they can modify your code if they have
to. Half of your lab grade will be determined by your programming
This is a guide to help you better understand what we are looking for
when we look at your labs. As the semester progresses there will be
steeper penalties for styling mistakes. So, get into the habit of
writing good labs from the beginning. After writing your lab, be sure
to look over your code and your style.
Comments are extremely important. Take some care to write accurate
yet concise comments.
- Be specific with your comments. What happens when the mouse
is pressed? What is the FilledRect used for? Your
comments should describe the intent of the code. What are you
trying to accomplish with this piece of code?
- Do not make your comments too long. Any line of comment or
code that is over 80 characters will not print. If it does not
print, the TA will not be able to read it. Consider revising or writing it
on multiple lines.
- Do not overcomment! Overcommenting can make the program
hard to read just as much as under-commenting. Do not comment
every line. If they are simple instructions, most people will
understand them without your comments. If you think you need
commenting, try commenting chunks of code under the same comment.
- Delete any extraneous code that is not used. You would not
hand in an English paper with crossed out lines. Similarly, you
should not hand in a lab with commented out code. Remove all code
that you comment out.
You should write comments for:
- Class (Program): At the top of each class, you should write
your name, date of creation, and a brief description of what the
class is for. If you decide to do more than the assignment
requested, you should describe these "extra" features in the
program under the class description. Sometimes it's hard to tell
a bug from a feature.
- Methods: Above each method heading there
should be a brief description of what the method does. You should
also describe what each parameter means and what the return result
means. If the method code is simple you do not need to comment in
the method body. If the method body is complicated, you might
want to add some comments to certain areas that you deem to be
complicated. Be careful not to overcomment!
- Variables and constants: In general, variables and constants
should all have comments as to what the variable is used for. For
example a good comment for your variable Line diagonal
in NoClicking would be: // the slash in the
prohibit sign. Occasionally several closely related variables or
constants can be grouped together under the same comment.
Blank lines are used to delineate different areas of the code. The
instance variable declarations at the top of your program should be
separated from the header of the class and the header of the first
method. There should always be space between methods. It is
advisable to break up long method bodies and long declarations into
logical pieces. Always start a new line after the semicolon.
Always leave a blank line before a comment line.
You should always choose names that suggest the meanings of the things
being named. If the purpose of a method is to draw a rectangle, then a
good name for that method is drawRect. If there is a
variable of type FilledRect that is used as the stem of a
stop sign, then a good name would be stem or
- Names that have nothing to do with the program are very bad
names! Ex. FramedRect frodo
- Names that are not specific or descriptive enough are
generally bad names. Ex. Line line or Line l
are not as good as Line foulLine if the line represents
a foul line.
- Try not to name objects sequentially. You should only do
this when the objects are related in some way that is not
otherwise expressible. Ex.,
FramedRect box1, FramedRect box2,
FramedRect box3 are not as good as darksBasket,
whitesBasket, and colorsBasket if the rectangles
represent laundry baskets for clothes of specific colors.
By convention, constants (indicated by "static final" in
Java) are all capital letters, classes begin with uppercase, variable
and method names begin with lowercase, while uppercase is used to start
new words in multi-word names.
Instance variables should never be declared to be public. Instance
variables should only be used when a value must be saved for use
after a constructor or method has been completed. Otherwise local
variables should be used.
Your program should be organized as neatly as possible. You might find it helpful
to select BlueJ's Auto-layout format command from the Edit menu to keep your program