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--- guides:programstyle:comments [2020/08/18 11:02] – created wikiadmin
+++ guides:programstyle:comments [2024/07/25 15:01] (current) – external edit 127.0.0.1
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 */
 </code>
+==== Comments Before Functions ====
+Functions should be proceeded by a block comment which describes at minimum
+  * A narrative describing the purpose of the function
+  * The input and output to the function
+    * Please note, this is a description of the parameters
+    * Input represents values passed into the function
+    * Output represents values returned or passed out of the funciton
+    * Input/Output represents values that are passed in, but may be changed
+  * Pre/post conditions for the function
+  * Special notes if required
+    * Explain any special algorithms
+    * Source of the function
+<code c++>
+/*
+    Function: GetWord
+    This function is responsible for interacting with the user to get a word that matches the given
+    description.  The function will ignore any extra input on the same line as the word.
+    Input:
+        description: a string which describes the word required
+                    example: "a noun"
+    Output:
+         word: the word the user has provided
+    Notes: This function uses cin.ignore to ignore all input after the first word.
+           A word is described as any collection of non-white space characters.
+    Preconditions: none
+    Post conditions: at least one word has been read from the input stream
+                    any input after the first word, up to 1000 characters will be ignored.
+</code>
+==== Comment Placement in Code ====
+Single line comments should be placed before sections of code which need explanation.
+Comments should begin in line with the code which is being documented:
+An acceptable example:
+<code c++>
+    // Read the input from the user and ignore any extraneous output
+    cin >> word;
+    cin.ignore(1000,'\n');
+</code>
+An unacceptable example:
+<code c++>
+// Print a line of the story filling in the blank
+       cout << line1Part1 << nounResponse << " " << line1Part2 << endl;
+</code>
+Comments should generally not be placed on the same line as code.  This guideline may be violated when declaring variables.
+The following example is not acceptable.
+<code c++>
+       cout << endl;    // done with output, print an endl
+</code>
+Use comments to supplement the understanding of major sections of code.  Only rarely should comments be used on every line of code.  The following is not an acceptable use of documentation.
+<code c++>
+// Get the noun from the user
+noun = GetWord("a noun");
+// Get the adjective from the user
+adjective = GetWord("an adjective");
+// Get the action verb from the user
+actionVerb = GetWord("an action word");
+</code>
+The code above is mostly self documenting due to identifier choice, so a single comment would be more appropriate
+<code c++>
+// Get the words from the user
+noun = GetWord("a noun");
+adjective = GetWord("an adjective");
+actionVerb = GetWord("an action word");
+</code>
+Finally, most comments in code should employ a c++ style line comment.  This allows the programmer to comment out large blocks of code with c style comments.
+==== Comment Contents ====
+Comments should describe the code, however comments should not repeat the code.
+An acceptable example:
+<code c++>
+// use the Pythagorean theorem (a^2+b^2 = c^2) to find the length of the third size.
+hypot = sqrt(sideA * sideA + sideB * sideB)
+</code>
+An unacceptable example:
+<code c++>
+// c = sqrt(a*a + b*b)
+hypot = sqrt(sideA * sideA + sideB * sideB);
+</code>
+In the above example, the comment provides NO additional information.  It is a duplication of the code.  This could be very detrimental if the original code was in error and later corrected, but the comment was not updated.  In that case, a future reader of the code would be further confused by the comment.
+In general, comments should support a knowledgeable programmer.