The comments in C are human-readable explanations or notes in the source code of a C program. A comment makes the program easier to read and understand. These are the statements that are not executed by the compiler or an interpreter.
It is considered to be a good practice to document our code using comments.
When and Why to use Comments in C programming?
- A person reading a large code will be bemused if comments are not provided about details of the program.
- C Comments are a way to make a code more readable by providing more descriptions.
- C Comments can include a description of an algorithm to make code understandable.
- C Comments can be used to prevent the execution of some parts of the code.
Types of comments in C
In C there are two types of comments in C language:
- Single-line comment
- Multi-line comment
1. Single-line Comment in C
A single-line comment in C starts with ( // ) double forward slash. It extends till the end of the line and we don’t need to specify its end.
Syntax of Single Line C Comment
// This is a single line comment
Example 1: C Program to illustrate single-line comment
// C program to illustrate // use of single-line comment #include <stdio.h> int main( void )
{ // This is a single-line comment
printf ( "Welcome to GeeksforGeeks" );
return 0;
} |
Welcome to GeeksforGeeks
Comment at End of Code Line
We can also create a comment that displays at the end of a line of code using a single-line comment. But generally, it’s better to practice putting the comment before the line of code.
Example:
// C program to demonstrate commenting after line of code #include <stdio.h> int main() {
// single line comment here
printf ( "Welcome to GeeksforGeeks" ); // comment here
return 0;
} |
Welcome to GeeksforGeeks
2. Multi-line Comment in C
The Multi-line comment in C starts with a forward slash and asterisk ( /* ) and ends with an asterisk and forward slash ( */ ). Any text between /* and */ is treated as a comment and is ignored by the compiler.
It can apply comments to multiple lines in the program.
Syntax of Multi-Line C Comment
/*Comment starts continues continues . . . Comment ends*/
Example 2: C Program to illustrate the multi-line comment
/* C program to illustrate use of multi-line comment */ #include <stdio.h> int main( void )
{ /*
This is a
multi-line comment
*/
/*
This comment contains some code which
will not be executed.
printf("Code enclosed in Comment");
*/
printf ( "Welcome to GeeksforGeeks" );
return 0;
} |
Welcome to GeeksforGeeks