Thread: how do i create a header file?

can anyone explain to me the steps in creating header file. the book talks about header files, how to include them and what they do, but it doesnt say how to create 1, like the step by step process. do i create it the same way i create a .cpp file? but with .hpp extension?

1. Create a text file named whatever.h (or .hpp)
2. You're done, what a genius you are now!

lol, does it have to b in the same directory as the .cpp file? i guess so right?

Not necessarily, you can do something like this:

#include "myfolder\myheader.h"

or if it's in a folder above the current one:

#include "..\myheader.h"

im having a problem... when i compile the prog, i get this

Code:

c:\program files\microsoft visual studio\myprojects\aprogram\rect.cpp(40) : fatal error C1075: end of file found before the left brace '{' at 'c:\program files\microsoft visual studio\myprojects\aprogram\rect.hpp(21)' was matched

any ideas?

in the Rect.hpp thers 2 classes with matching braces. in the rect.cpp theres 3 pairs of matching braces and when i click on the error it sends me at the brace at the end of the file after return 0; .. i dont get it

Code:

#include <iostream>
class Point  //holds x, y coordinates
{
	//no constructor, use default
public:
	void SetX(int x){itsX =x;}
	void SetY(int y){itsY =y;}
	int GetX() const {return itsX;}
	int GetY()const {return itsY;
private:
	int itsX;
	int itsY;
};//end of point class declaration

class Rectangle
{
	public: 
			Rectangle (int top, int left, int bottom, int right);
			~Rectangle(){}

			int GetTop()const {return itsTop;{
			int GetLeft()const {return itsLeft;}
			int GetBottom()const{return itsBottom;}
			int getRight() const {return itsRight;}

			Point GetUpperLeft() const {return itsUpperLeft;}
			Point GetLowerLeft() const {return itsLowerLeft;}
			Point GetUpperRight() const {return itsUpperRight;}
			Point GetLowerRight() const {return itsLowerRight;}

			void SetUpperLeft(Point Location) {itsUpperLeft = Location;}
			void SetLowerLeft(Point Location) {itsLowerLeft = Location;}
			void SetUpperRight(Point Location) {itsUpperRight = Location;}
			void SetLowerRight(Point Location) {itsLowerRight = Location;}


			void SetTop(int top) { itsTop =top;}
			void SetLeft(int left) {itsLeft =left;}
			void SetBottom (int bottom) { itsBottom = bottom;}
			void SetRight (int right) {itsRight = right;}

			int GetArea()	const;
	private:
			Point itsUpperLeft;
			Point itsUpperRight;
			Point itsLowerLeft;
			Point itsLowerRight;
			int	  itsTop;
			int   itsLeft;
			int   itsBottom;
			int   itsRight;
};
			//end rect.hpp

rect.cpp

Code:

#include "Rect.hpp"
Rectangle::Rectangle(int top, int left, int bottom, int right)
{
	itsTop =top;
	itsLeft = left;
	itsBottom = bottom;
	itsRight = right;

	itsUpperLeft.SetX(left);
	itsUpperLeft.SetY(top);

	itsUpperRight.SetX(right);
	itsUpperRight.SetY(top);

	itsLowerLeft.SetX(left);
	itsLowerleft.SetY(bottom);
}

//compute area of the rectangle by finding cornersides,
//establish width and height and then multiply

int Rectangle::GetArea() const
{

	int Width = itsRight - itsLeft;
	int Height = itsTop - itsBottom;
	return(Width * Height);
}
int main()
{
	//intitialize a local Rectangle variable
	Rectangle MyRectangle (100,20,50,80);

	int Area = MyRectangle.GetArea();
	std::cout <<"Area: "<<Area <<"\n";
	std::cout <<"Upper Left X coordinate: ";
	std::cout <<MyRectangle.GetUpperLeft().GetX();
	return 0;
}

found it lol

Code:

int GetY()const {return itsY;

damn

yep, thanks ehehe

just a suggestion

Code:

private:
	Point itsUpperLeft;
	Point itsUpperRight;
	Point itsLowerLeft;
	Point itsLowerRight;
	int   itsTop;
	int   itsLeft;
	int   itsBottom;
	int   itsRight;

change all those to upperLeft, upperRight, so on.

You should also use so called Inclusion Guards in your header files. If you (accidently or not) include the header file twice you will get multiple definition errors.

Point.h:

Code:

#ifndef SOME_UNIQUE_NAME
#define SOME_UNIQUE_NAME

... //Stuff

#endif

Even if the file is included multiple times, the stuff between #ifndef/#endif will only be included once.

thanks for the heads up, i really just started learning about headers i dont think im in a position to do complicated stuff that will require a lot of header files. but i got a question for u Magos, how did u write that War3 SLK editor. id like to do something like that with a prog i got in the "to do list" after i get a bit comfortable and familiar with c++. any special topics in order to write something like that?

edit: btw forgot to say that ur name = magician in greek. eheh