C++ In a Nutshell

Comments

Comments start with /* and end with */. These comments do not nest. For example:

/* this is a comment /* still a comment */
int not_in_a_comment;

A comment can also start with //, extending to the end of the line. For example:

const int max_widget = 42; // Largest size of a widget

Within a /* and */ comment, // characters have no special meaning. Within a // comment, /* and */ have no special meaning. Thus, you can “nest” one kind of comment within the other kind. For example:

/* Comment out a block of code:
const int max_widget = 42; // Largest size of a widget
*/

///* Inhibit the start of a block comment
const int max_widget = 10; // Testing smaller widget limit
//*/

A comment is treated as whitespace. For example, str/*comment*/ing describes two separate tokens, str and ing.