2.comment:-
A “comment” is a sequence of characters beginning with a forward slash/asterisk combination (/*) that is treated as a single white-space character by the compiler and is otherwise ignored. A comment can include any combination of characters from the representable character set, including newline characters, but excluding the “end comment” delimiter (*/).
The Microsoft compiler also supports single-line comments preceded by two forward slashes (//)
example :-
/* Comments can contain keywords such as
for and while without generating errors. */
and
// This is a valid comment