How to comment a few lines, with comments inside

Question

Hello.. I have a program like this

int main(){ 

    char c;
    int i; /* counter */
    double d;

    return 0;
}

if I want to comment out char, int and double, and just have return uncommented, can I do it? the comment that's already there stops the comment.. Is there an easy/fast way to comment that out?

Answer 1

int main(){ 

/*
    char c;
    int i; // counter
    double d;
*/
    return 0;
}

Answer 2

int main(){ 
#if 0
    char c;
    int i; /* counter */
    double d;
#endif
    return 0;
}

Not strictly a comment, but the effect is what you want and it's easy to revert.

This also scales well to larger code blocks, especially if you have an editor that can match the start and end of the #if..#endif.

Answer 3

If your compiler supports the // notation for comments (non-standard in C, but quite commonly supported), use an editor that can toggle a whole block of lines with these.

Answer 4

In C99

int main(){ 

//    char c;
//    int i; /* counter */
//    double d;

    return 0;
}

Answer 5

There are a lot of Editors / IDEs which support commenting/uncommenting with Hotkeys. This is a very useful feature. In Kate/KDevelop the hotkey is Ctrl+D.

This also is described (along with other IDEs supporting this feature) in THIS question.

Answer 6

If you ever are tempted to put the name of a variable in comments like in the example, do this instead:

int counter; 

Answer 7

I'm partial to:

int main(){ 

#ifdef USE_DISABLED_CODE
    char c;
    int i; /* counter */
    double d;
#endif

    return 0;
}

Use a terse name like 'CODE_REMOVED_FOR_TESTING_PURPOSES' or 'REMOVED_FROM_E3_BUILD', and don't define it, and you've left yourself a terse comment about why the code is disabled (which will show up if you do a find in all files for #ifdef).