General Style Deductions

Students in CSE143 are expected to demonstrate good programming style in their homework solutions. Every homework assignment will describe specific style requirements and expectations that students should keep in mind when writing their solutions. This page lists general style issues that are likely to be relevant to multiple assignments. This list includes common style mistakes but does not list every possible style mistake.

TAs provide feedback on graded homework assignments and often give a "-0" warning to indicate a style issue that is not being penalized but might be in a future assignment. The list below indicates general style issues that will not be graded as "-0". Homework assignments are listed in reverse order because once a style issue is included for one homework, it is included for all future homeworks. The list is not meant to be exhaustive, although it includes the most common style issues.

  • Homework 8: Huffman

    • no new style errors

  • Homework 7: 20 Questions
    • class design errors:
    • data structure errors:
      • not using x=change(x) when appropriate to simplify code
      • poor choice of constructors for a node class (e.g., unused constructors or just a zero-argument constructor)
    • miscellaneous errors:
      • poor choice of constructor (e.g., setting fields immediately after construction when they could have been set by using a different constructor)
  • Homework 6: Anagram Solver

    • no new style errors

  • Homework 5: Grammar Solver
  • Homework 3: Assassin
  • Homework 2: Guitar Hero
  • Homework 1: LetterInventory
    • commenting errors:
      • class header missing or doesn't describe both student and program
      • method header missing or does not document pre and post-conditions
      • method header does not describe exceptions that are thrown when preconditions are violated, including the specific type of exception and the conditions under which it is thrown
      • method header does not document important behavior including subtle cases like an empty structure or a search value not found
      • blind copying of text from assignment writeup
    • readability errors:
      • bad indentation
      • some method or constructor does not have a blank line before it
    • control structure errors:
    • data structure errors:
      • extra data structures that aren't necessary
      • bad usage of arrays (e.g., funky/incorrect indexing/usage)
    • class design errors:
    • miscellaneous errors:
      • using a specific numerical value when the value can be obtained in a more general way (e.g., even if an array called data is expected to be of length 100, code to manipulate it after construction should use data.length instead of 100)
  • note: "e.g." should be read as "for example" and "i.e." should be read as "in other words"

    In general, once a class has been discussed, it is available for use by students. For example, the String class and the Arrays class were covered in the CSE142 course, so it is reasonable to assume that you can use methods from those classes without asking permission. Student should realize, however, that saying that you are not forbidden from using a certain construct is not the same thing as saying that it is a good idea to use a certain construct. We don't give advice to students about which constructs to use. You have to use your best judgement to decide and you might lose style points if you make a poor choice. In addition, there are some constructs that you are not allowed to use, as described in the next paragraph.

    Java has grown to be a complex language with many features. We don't have time to teach all of these features in CSE143. We have a general rule that students should not use "advanced" material that we have not covered in class. In addition, we have identified several Java features that we do not want students to use. It is not bad style to use these features, but we want to have a level playing field for all students. For any one of these features, we prefer that either everyone in the class knows about it and can use it or nobody is allowed to use it. The following features should not be used in CSE143 homework or exam solutions:

    Many students find themselves wondering, "What is that feature you are describing?" If you don't recognize it, then you're unlikely to use it, so the best answer is, "Something that we have decided not to teach you in this class so that we will be able to focus on the really important concepts you need to learn."