Internal Documentation Conventions Kinds of comments javadoc doc comments describe the user interface What the classes interfaces fields and methods are for How to use them Obviously the maintainer needs to know what the code does In addition the maintainer needs to understand how the code works Kinds of internal comments Standard C style comments One line and end line comments a one line comment is on a line by itself x 0 an end line comment follows code These are both internal comments seen only by someone looking at your code Internal comments are only for maintainers But avoid things that would embarrass you to a user Which kind of internal comment Rule 36 Use standard comments to comment out code without removing it I don t agree Suggested because it s usually easy to do but BlueJ s comment and uncomment commands make it easier to use one line comments Standard comments cannot be nested so it s tricky commenting out code with comments One line comments don t have this problem Explaining the code I Rule 59 Add internal comments only if they will aid in understanding your code Don t repeat the javadoc comments Don t put in comments to explain things that are obvious from the code Don t put in irrelevant or useless comments Diamondbacks beat the Yankees 3 2 Always put comments before the code they describe never after the code Explaining the code II Rule 37 Use one line comments to explain implementation details One line comments are also good for writing reminders for yourself about things you still need to work on need to rewrite this if more than one rabbit I like to use one line comments to tell what the next block of code is going to do put the rabbit in a random location End line comments I Rule 61 Avoid the use of end line comments This rule is largely to prevent overly long lines But Rule 62 Explain local variable declarations with an end line comment int edgeDistance distance to the nearest edge And Rule 64 Label closing braces in highly nested control structures end switch end if end for j end for i End line comments II I also find end line comments useful for an else that is a long way from its if if distance 5 a lot of code in between else distance 5 Unresolved issues Rule 63 Establish and use a set of keywords to flag unresolved issues I personally like to use the canvas isn t being redrawn properly More specific flags are likely to be used in large projects Intentionally missing break Rule 65 Add a fall through comment between two case labels of a switch statement if no break statement separates those labels The switch statement is so badly designed that forgetting the break is a common error To keep an intentionally missing break from being corrected add a comment Label empty statements Sometimes you intentionally use a loop with an empty statement body Rule 66 Label empty statements while c reader read space Empty body I prefer a different solution use an empty block as the statement body while c reader read space Don t repeat the code Rule 60 Describe why the code is doing what it does not what the code is doing Another way of saying this is Comments should not echo code Here s a typical example of a bad comment count 0 set count to zero You should assume that anyone reading your internal comments knows some Java Use the active voice Rule 34 Use the active voice and omit needless words zero out the array each of the elements of the array is set to zero by the following loop Writing comments is still writing all the rules for good writing apply to comments Best reference The Elements of Style by Strunk and White Debugging statements We sometimes put in debugging statements that we plan to remove afterwards Simple trick start these temporary statements in the first column so you can find them easily boolean legalLocation int row int col System out println legalLoc row col return row 0 row numRows column 0 column numCols The End
View Full Document
Unlocking...