How to use files in other directory?

I wrote codes for some file that were ".h" files.And now I want to use them in other programs..how do I have to declare to use them?please help me..thanks very much....

Code:

---

#include "myLibrary.h"

// or if they're in a sub directory...

#include "directory/myLib.h"

---

Use the -I command line option (pretty universal as far as command line flags go)

If you have
#include <myheader.h>

Then
g++ -I/path/to/headers prog.cpp

would look to see if /path/to/headers/myheader.h existed, and if it does it would be included.

Example I have a "temp.h" file in directory "C:\School\programs\temp.h" and program that I want to use this file is in "D:\example\usetemp.cpp".How do I have to declare to use "temp.h"?....

I already said how.

If you want detailed instructions for your specific compiler / IDE, you're going to have to say which one it is.

Start in project - > settings -> compiler sort of place and then look for include paths.