How many ways can comments be added in a C program?

Question

When I was solving a problem from the famous KR book to remove comments from a c program I have searched over the internet to know all the possible cases where comments can be inserted in a C program and didn't find any complete answer of this question. So here I am adding the answer to this question. feedback is welcomed.

Answer 1

How many ways are there to insert comments in a C program?

1. When a single line comment symbol is inserted anywhere in a line everything that appears before a newline is part of the comment.

2. Any type of comment symbol can appear inside a double-quoted string — so single-line and multi-line comment symbols appearing inside double quotes are not a comment; they are normal text.

3. Multi-line comments can be placed anywhere in the source code where you can put a blank.

4. In C, comments cannot be nested. Inserting a multi-line comment start symbol inside another multiple line comment will truncate the parts of comments that come after the first comment terminating symbol. Check the example of #4 to understand clearly.

#include <stdio.h>
#define TABSIZE /*false comment*/ 8

// this is a demo program. /* comment here */           XD example of #1

int main()
{
    printf("#1  :- /* multiple */ and // single \n"); // example of #2

    char str[40] = "/* multiple */ and // single"; // example of #2
    printf("#2  :- %s\n", str);

    char one /* example of #3 */ = 'x'; // example of #3
    char two /* example of #3 */ = 'y'; // example of #3
    printf("#3  :- %c and %c\n", one, two);

    return /*example of #3 */ 0; // example of #3

    /*(start1) this is a comment /*(start2) trying to-      -- example of #4
     insert an nested comment here */
    //  (e2) this part is not considered as comment */(e1).
    //  so to successfully run the program this part of the
    //  comment  is handled by single line comment symbol '//'.
    //  remove all the '//' to see what happens.
}