can a C/C++ prog. runs without header file
Question
Answers
-
Sanket_Shah_734609 wrote: @ Varun,
The idea of yours is the most silly thing to do.
Silly it is, but its better than writing all of the header contents on your own..
I just gave a possible answer..
Also, using printf & scanf without header file is compiler dependent.. some of the compiler would allow you to do it some will not.. Also there are different versions of Turbo C, so it can create a difference too.. but the thing is that you can write a C/C++ prog without the header file...
But, Anyways header file only include the Prototype of the functions that we are going to use.. It does not contain the whole code.. Like there is only the prototype of printf and scanf in stdio.h
So just check out the prototype of the functions and declare them your self.. this will be enough to run your program.. you can do this for any funtions that you use.. you only need to declare the prototype of the function.. The linker will attach this funtions to your code at the time of linking...
All replies
-
Well the answer is yes.. because in some compilers the functions of printf and scanf are integrated in the compiler, so you dont need to declare a header file for them.. so you can run a program which has only a printf and scanf function without the header file...'
-
Ya thatz true.. but the thing is that you can write a program without header files... n that is a fact
-
I know that, but you must give strong grounds to believe it. So please give appropriate responses next time.
-
Or the best of all, just copy the whole header file in the program, It is equivalent to include the file, but you are not doing it explicitly...
-
Sanket_Shah_734609 wrote: @ Varun,
The idea of yours is the most silly thing to do.
Silly it is, but its better than writing all of the header contents on your own.. I just gave a possible answer..
Also, using printf & scanf without header file is compiler dependent.. some of the compiler would allow you to do it some will not.. Also there are different versions of Turbo C, so it can create a difference too.. but the thing is that you can write a C/C++ prog without the header file...
But, Anyways header file only include the Prototype of the functions that we are going to use.. It does not contain the whole code.. Like there is only the prototype of printf and scanf in stdio.h
So just check out the prototype of the functions and declare them your self.. this will be enough to run your program.. you can do this for any funtions that you use.. you only need to declare the prototype of the function.. The linker will attach this funtions to your code at the time of linking... -
Yours is really a nice reply Kanav.
You deserve getting your reply marked as answer.
-
Kanav's reply was excellent... In effect, you can write any program without including any header files as long as you stick to basic C. I/O and floating point are not defined to be within basic C language itself, so you'll have to include header files for using them. Other than that, we can use all declarations, assignments, calculations, looping, branching, etc., without using any header files at all...
Even for I/O, you might be able to do it yourself using low level manipulation. For eg., I remember reading in 'Let us C' by Yashavant Kanetkar that you can output text the monitor by storing the address of video memory in a far pointer and writing the content to it... Quite some work, but possible...
