### 2.8.2 Entering comments

You can annotate an Xcas session by adding comments. You can enter a comment on the current line at any time by typing Alt+C. The line will appear in green text and conclude when you type Enter. (To force a new line, press Shift+Enter.) Comments are not evaluated and so have no output. If you have started entering a command when you begin a comment, the command line with the start of the command will be pushed down so that you can finish it when you complete the comment.

You can open the browser using a comment line by entering the web address beginning with the @ sign. For example, if you enter the comment line

> The Xcas homepage is at
> @www-fourier.ujf-grenoble.fr/~parisse/giac.html

then the browser will open to the Xcas home page.

To add a comment to a program, rather than a session, use the comment command.

- comment takes str, a string.
- comment(str) makes str a comment.

Alternatively, any part of a program between // and the end of the line is a comment. So both

bs():={ comment("Hello"); return "Hi there!"; }

and

bs():={ // Hello return "Hi there!"; }

are programs with the comment “Hello”.