Code comments - // and /*. */

C# supports two different forms of comments. Single line comments start with // and end at the end of that line of code. Multiline comments start with /* and end with */. The following code shows an example of each:

C#

// This is a single line comment.

/* This could be a summary of all the
   code that's in this class.
   You might add multiple paragraphs, or links to pages
   like https://learn.microsoft.com/dotnet/csharp.
   
   You could even include emojis. This example is 🔥
   Then, when you're done, close with
   */

The multi-line comment can also be used to insert text in a line of code. Because these comments have an explicit closing character, you can include more executable code after the comment:

C#

public static int Add(int left, int right)
{
    return left /* first operand */ + right /* second operand */;
}

The single line comment can appear after executable code on the same line. The comment ends at the end of the text line:

C#

return source++; // increment the source.

Some comments start with three slashes: ///. Triple-slash comments are XML documentation comments. The compiler reads these to produce human documentation. You can read more about XML doc comments in the section on triple-slash comments.