CSE 142: Computer Programming I, Winter 2020

• bad use of if/else (e.g., empty branch, unnecessary tests, redundant branches that can be combined with logical or)

• initializing non-final data fields outside of a constructor
• non-private data fields

• unnecessary return from a method

• extra data structures that aren't necessary
• bad usage of arrays (e.g., funky/incorrect indexing/usage)

• including code in a loop that should be executed once either before or after the loop

• trivial methods

• unnecessarily inefficient code (e.g., constructing a new object on every iteration of a loop when it could have been constructed once before the loop or including an unnecessary test in a conditional)
• using \t instead of individual spaces to align output

• method header does not describe the action/behavior of the method
• method header does not describe the purpose of each parameter or does not describe the meaning of the return value of a non-void method

• lines over 100 characters
• nondescriptive variable names

• using incorrect if/else structure
• failing to factor out redundant code in if/else structures

• do-all methods (i.e. methods that contain most or all of the work that should be done in main)

• incorrect use of type (e.g., double instead of int, int instead of boolean, String instead of char for a value known to be exactly one character)
• using \n with print/println or to produce more than one line of output with a single printf
• not combining print/print or print/println statements when possible
• using print/println/printf with the empty string ("")
• constructing more than one Scanner for console input

• not following Java naming conventions (e.g., not using camel case, not using uppercase letters and word-separating underscores for constants)
• not including a blank line between methods
• long lines

• unused parameters or passing a constant as a parameter

• method header comment missing or does not adequately describe what the method does
• bad indentation

• bad use of loops (e.g., 1 to 1 loops, including an unnecessary check before a loop that repeats the loop test)

• nondescriptive method names

• incorrect constant declaration (e.g., not final, not static)

• class header missing or doesn't describe both student and program

• no indentation

• use of \n or advanced material (see below)

The following features should NEVER be used in a CSE142 programming assignment or exam solution (unless otherwise specified by the assignment or problem):

• break, continue, or return from a void method
• the System.exit method
• the switch statement
• try/catch
• annotations
• the <> operator
• the var keyword
• Java 8 functional features (e.g., lambdas, streams, method references)
• the toCharArray, join, and matches methods of String
• the StringBuilder, StringBuffer, StringJoiner, StringTokenizer classes
• the methods Arrays.fill, Arrays.asList, Arrays.copyOf, Arrays.copyOfRange, and Arrays.sort
• multi-dimensional arrays
• the toArray and clone methods of ArrayList
• the methods Collections.copy and Collections.sort

(Don't worry if you are not familiar with one of the features listed above. You can simply think of these as Java features we have chosen not to teach in this class so that we can focus on other important concepts instead.)