C Comments
Comments in C
Comments can be used to explain code, and to make it more readable. It can also be used to prevent execution when testing alternative code.
Comments can be singled-lined or multi-lined.
Single-line Comments
Single-line comments start with two forward slashes (//
).
Any text between //
and the end of the line
is ignored by the compiler (will not be executed).
This example uses a single-line comment before a line of code:
This example uses a single-line comment at the end of a line of code:
C Multi-line Comments
Multi-line comments start with /*
and ends with */
.
Any text between /*
and */
will be ignored by
the compiler:
Example
/* The code below will print the words Hello World!
to the screen, and it is
amazing */
printf("Hello World!");
Try it Yourself »
Single or multi-line comments?
It is up to you which you want to use. Normally, we use //
for short comments, and /* */
for longer.
Good to know: Before version C99 (released in 1999), you could only use multi-line comments in C.