[asaljoha]

Hi can anyone explain to me What is the difference between #include<headerfile.h> and #include "headerfile.h"?

Thanks a lot..................

[Tom9729]

You use quotes when you're specifying the path of the header file.

You use the "<...>" when the header file is in a system directory like /usr/include (Unix, in Windows I think it's somewhere in one of the system folders).

You can usually specify an additional include directory (so you can use the "<...>") as a compiler flag (depending on which compiler you use).

For example, since stdio.h is in my system's include path, I can include it by doing #include <stdio.h>. However it would also work if I used quotes and specified the path like this #include "/usr/include/stdio.h".

[MorphiusFaydal]

The <...> are for system headers. (The default includes, like iostream, stdlib, etc.).

The "..." are for custom headers, i.e., ones you've written for your project.

[asaljoha]

Thanks. it helps a lot.

[Nayana]

A difference is that in the quoted form i.e. #include "something" the preprocessor will search the paths of all files in the project that include the same file.

With the angled bracket form, that is not done, it only searches the INCLUDE environment variable, and the path specified in the "/I" compiler option. The quoted form does this as well.

Have a codeful day

This post has been edited by Nayana: 27 February 2008 - 07:11 PM

[selloorhari]

#include <file>
This variant is used for system header files. It searches for a file named file in a standard list of system directories.
#include "file"
This variant is used for header files of your own program. It searches for a file named file first in the directory containing the current file, then in the quote directories and then the same directories used for <file>.
Check This link:

developer.apple.com/DOCUMENTATION/DeveloperTools/gcc-4.0.1/cpp/Header-Files.html#Header-Files

[Tom9729]

Four nearly identical answers?

If ever a thead needed closing, this is it.

[MorphiusFaydal]

Tom9729, on 28 Feb, 2008 - 12:34 PM, said:

Four nearly identical answers?

If ever a thead needed closing, this is it.

I think I streamlined your answer.