Using a doc comment instead of a regular comment enables dartdoc to find it and generate documentation for it.
/// The number of characters in this chunk when unsplit.
int get length => ...
You are allowed to use most markdown formatting in your doc comments and dartdoc will process it accordingly using the markdown package.
/// This is a paragraph of regular text.
///
/// This sentence has *two* _emphasized_ words (i.e. italics) and **two**
/// __strong__ ones (bold).
///
/// A blank line creates another separate paragraph. It has some `inline code`
/// delimited using backticks.
///
/// * Unordered lists.
/// * Look like ASCII bullet lists.
/// * You can also use `-` or `+`.
///
/// Links can be:
///
/// * http://www.just-a-bare-url.com
/// * [with the URL inline](http://google.com)
/// * [or separated out][ref link]
///
/// [ref link]: http://google.com
///
/// # A Header
///
/// ## A subheader