What are the two types of comments in c programming language and how do they differ?

Answer 1

C uses two types of comment: single-line and multi-line. The multi-line comment originated in C while the single-line comment originated in C++. Both types are supported by both languages today.

A single-line comment begins with the double-slash token (//) and extends to the end of the line.

A multi-line comment begins with the slash-asterisk token (/*) and ends with the asterisk-slash token (*/).

Examples:

int x; // this is a single-line comment

/* this is multi-line comment, typically

used to introduce a function or class */

Note that since multi-line comments are fully-delimited, they may be used within the middle of a line of code. This is most useful when a function is forward-declared with a default value for one of its arguments and you wish to include that default value in the function definition (something which is not permitted under the one-definition rule):

void f (int = 0); // declaration

void f (int x /* = 0 */) { // definition

}

Such usage is really only of use to the function maintainer, as a reminder that the function has a default value.

We can also use this technique when a function has an argument that is reserved for future use, but is otherwise unused in the current version of the function:

void g (int); // declaration

void g (int /* unused */) { // definition

}

Again, such usage is only of use to the function maintainer.

Answer 2

C supports two comment types: single-line and multi-line. The single-line comment was inherited from C++.

// this is a single-line comment: it extends to the end of the line

/* this is a multi-line comment:

it extends until the end-of-comment marker */

Answer 3

The two types of comment in C Programming are: In-Line Comment and Block Comment.

In-Line Comment (denoted by double slash //) is use to add comment for a specific line only. Codes that will come after these double slash will be treated as a comment and will not actually read by the program.

Block Comment (denoted by slash-asterisk and asterisk-slash /* */) is use to add comment in a block style. Anything that is inside the block comment will be treated as a comment, no matter how many lines it takes. Unlike the In-line comment, codes after the asterisk-slash (*/) will be treated as codes and will be read by the compiler.