Comments in your webserver

You already know that comments are a really way to drop notes into your code.

A more technical way to understand them is that comments are effectively a way to remove the comment text from the language parser. The parser is the process which breaks down your code into tokens based on the syntax of the language. A good programmer needs to understand this: it's how you don't accidentally comment-out things like closing tags or brackets, or try to put comments inside strings.

Comments can be very helpful as debugging placeholders, explainers as to why code is a particular way, or as documentation (many languages have automated ways to extract comments into project documentation: if you're interested in this for Python, see pydoc).

In your buggy editor webserver, there are two primary places you'll encounter comments (and write your own): Python and HTML.

Comments in Python

Comments in Python start with a # and continue to the end of the line. This is why you can add comments on the same line as a statement:

# this is a comment
# and so is this
#-----------------------------------

buggy = cur.fetchone()  # just get one of the records we've read

Comments in HTML

Comments in HTML start with  turns up. You cannot nest comments.

<!--  this is a comment -->
<p>
  This is a paragraph.
  <!-- another comment -->
</p>

<!--
    this is all a comment
    <p>
       so this paragraph will not display in the browser
       ...because it's inside the comment 
    </p>--> <p> I'm a paragraph</p>

<p>
  Another <!-- comment inside --> paragraph.
</p>

HTML comments are effectively at the element-level: as shown with the commented <p> above, they can contain other elements, or (of course) appear inside other elements' content... but don't use them to try to "comment-out" attributes within an element.

Comments in other places

Cascading style sheets (CSS)

Comments in CSS start with /* and end with */ and can run over many lines.

/* this is a comment 
   which may go over several
   lines */

h1 {
  color: red;  /* this is a comment  */
}
h2 { color: blue; }

JavaScript

There are two kinds of comment in JavaScript:

Anything after // is a comment until the end of the line.

Or anything between /* and */ is a comment over any number of lines.

let greeting = 'hello'; // this is a comment
/* this is
   a comment too 
   greeting = "goodbye"
*/
console.log(greeting); // writes "hello" to the console

SQL

Comments in SQL are preceded with two hyphens. Most of the SQL in your project is actually being quoted by Python (with the sqlite execute() function) so you might not come across a need for this:

-- this is inserting one record into the table
INSERT INTO buggies VALUES (qty_wheels) SET (4);

CS1999 Buggy Racing tech notes