C++ RSS C++ RSS

Adding memberfunctions into a class?

Please support our C++ advertiser: Intel Parallel Studio Home
Reply

•
•
Join Date: Sep 2004
Posts: 421
Reputation: JoBe is on a distinguished road 
Solved Threads: 4
JoBe's Avatar
JoBe JoBe is offline Offline
Posting Pro in Training

Adding memberfunctions into a class?

 
0
  #1
Nov 5th, 2005
Hello ladies and gents,

I was reading about how "Passing by References" for efficiency and there was a little program added wich shows what the difference is between passing by value and passing by reference is. The program is this one:

C++ Syntax (Toggle Plain Text) 
  1. #include <iostream>
  2.  
  3. using namespace std;
  4.  
  5. class SimpleCat
  6. {
  7. public:
  8. 	SimpleCat();
  9. 	SimpleCat (SimpleCat&);
  10. 	~SimpleCat();
  11. };
  12.  
  13. SimpleCat::SimpleCat()
  14. {
  15. 	cout<<"Simple Cat Constructor...\n";
  16. }
  17.  
  18. SimpleCat::SimpleCat (SimpleCat&)
  19. {
  20. 	cout<<"Simple Cat Copy Constructor...\n";
  21. }
  22.  
  23. SimpleCat::~SimpleCat()
  24. {
  25. 	cout<<"Simple Cat Destructor...\n";
  26. }
  27.  
  28. SimpleCat FunctionOne (SimpleCat theCat);
  29. SimpleCat *FunctionTwo (SimpleCat *theCat);
  30.  
  31. int main()
  32. {
  33. 	cout<<"Making a cat...\n";
  34. 	SimpleCat Frisky;
  35. 	cout<<"Calling FunctionOne...\n";
  36. 	FunctionOne (Frisky);
  37. 	cout<<"Calling FunctionTwo...\n";
  38. 	FunctionTwo (&Frisky);
  39.  
  40. 	return 0;
  41. }
  42.  
  43. SimpleCat FunctionOne (SimpleCat theCat)
  44. {
  45. 	cout<<"FunctionOne returning...\n";
  46.  
  47. 	return theCat;
  48. }
  49.  
  50. SimpleCat *FunctionTwo (SimpleCat *theCat)
  51. {
  52. 	cout<<"FunctionTwo returning...\n";
  53.  
  54. 	return theCat;
  55. }

No problem there, but, I decided to see wether I could change the program so "FunctionOne" and "FunctionTwo" where memberfunctions from SimpleCat, but, to no avail.

I thought that the following changes would be correct and lett me use this in the same way as the above example, but, that is not the case:

C++ Syntax (Toggle Plain Text) 
  1. #include <iostream>
  2.  
  3. using namespace std;
  4.  
  5. class SimpleCat
  6. {
  7. public:
  8. 	SimpleCat();
  9. 	SimpleCat (SimpleCat&);
  10. 	~SimpleCat();
  11.  
  12. 	FunctionOne (SimpleCat);
  13. 	*FunctionTwo (SimpleCat*);
  14. };
  15.  
  16. SimpleCat::SimpleCat()
  17. {
  18. 	cout<<"Simple Cat Constructor...\n";
  19. }
  20.  
  21. SimpleCat::SimpleCat (SimpleCat&)
  22. {
  23. 	cout<<"Simple Cat Copy Constructor...\n";
  24. }
  25.  
  26. SimpleCat::~SimpleCat()
  27. {
  28. 	cout<<"Simple Cat Destructor...\n";
  29. }
  30.  
  31. int main()
  32. {
  33. 	cout<<"Making a cat...\n";
  34. 	SimpleCat Frisky;
  35. 	cout<<"Calling FunctionOne...\n";
  36. 	Frisky.FunctionOne (Frisky);
  37. 	cout<<"Calling FunctionTwo...\n";
  38. 	Frisky.FunctionTwo (&Frisky);
  39.  
  40. 	return 0;
  41. }
  42.  
  43. SimpleCat::FunctionOne( SimpleCat theCat)
  44. {
  45. 	cout<<"FunctionOne returning...\n";
  46.  
  47. 	return theCat;
  48. }
  49.  
  50. SimpleCat::*FunctionTwo (SimpleCat *theCat)
  51. {
  52. 	cout<<"FunctionTwo returning...\n";
  53.  
  54. 	return theCat;
  55. }

The error messages that I get are these ones:
C++ Syntax (Toggle Plain Text) 
  1. error C2501: 'FunctionTwo' : missing storage-class or type specifiers
  2. error C2440: 'return' : cannot convert from 'class SimpleCat' to 'int'
  3.         No user-defined-conversion operator available that can perform this conversion, or the operator cannot be callederror C2501: 'FunctionTwo' : missing storage-class or type specifierserror C2440: 'return' : cannot convert from 'class SimpleCat *' to 'int'
  4.         This conversion requires a reinterpret_cast, a C-style cast or function-style cast
  5. error C2617: 'FunctionTwo' : inconsistent return statement

Can any of you please explain what I'm doing wrong

Thank you.
Reply With Quote Quick reply to this message  
•
•
Join Date: Aug 2005
Posts: 598
Reputation: SpS is on a distinguished road 
Solved Threads: 32
SpS's Avatar
SpS SpS is offline Offline
Posting Pro

Re: Adding memberfunctions into a class?

 
1
  #2
Nov 5th, 2005
Here Is the corrected Code...Code In Red Was Missing
#include <iostream>

using namespace std;

class SimpleCat
{
public:
	SimpleCat();
	SimpleCat(SimpleCat&);
	~SimpleCat();

	SimpleCat FunctionOne(SimpleCat);
	SimpleCat* FunctionTwo(SimpleCat*);
};

int main()
{
	cout<<"Making a cat...\n";
	SimpleCat Frisky;
	cout<<"Calling FunctionOne...\n";
	Frisky.FunctionOne(Frisky);
	cout<<"Calling FunctionTwo...\n";
	Frisky.FunctionTwo (&Frisky);
	
	return 0;
}
SimpleCat::SimpleCat()
{
	cout<<"Simple Cat Constructor...\n";
}

SimpleCat::SimpleCat (SimpleCat&)
{
	cout<<"Simple Cat Copy Constructor...\n";
}

SimpleCat::~SimpleCat()
{
	cout<<"Simple Cat Destructor...\n";
}

SimpleCat SimpleCat::FunctionOne( SimpleCat theCat)
{
	cout<<"FunctionOne returning...\n";
	
	return theCat;
}


SimpleCat* SimpleCat::FunctionTwo(SimpleCat *theCat)
{
	cout<<"FunctionTwo returning...\n";

	return theCat;
}
Reply With Quote Quick reply to this message  
•
•
Join Date: Sep 2004
Posts: 421
Reputation: JoBe is on a distinguished road 
Solved Threads: 4
JoBe's Avatar
JoBe JoBe is offline Offline
Posting Pro in Training

Re: Adding memberfunctions into a class?

 
0
  #3
Nov 5th, 2005
Thank you sunnypalsingh for your help :!:

Could you however explain why it is necessary to write the name of the class infront of the definition inside the class and twice infront of the declaration outside the class
Reply With Quote Quick reply to this message  
•
•
Join Date: Aug 2005
Posts: 598
Reputation: SpS is on a distinguished road 
Solved Threads: 32
SpS's Avatar
SpS SpS is offline Offline
Posting Pro

Re: Adding memberfunctions into a class?

 
0
  #4
Nov 5th, 2005
•
•
•
•
Originally Posted by JoBe
Could you however explain why it is necessary to write the name of the class infront of the definition inside the class and twice infront of the declaration outside the class
Well its the syntax of language.....
syntax
returntype classname ::functionname(arguments)

returntype-tells what the function is returning
classname-tells the scope of the function(which class does it belong to)
:: scope resolution operator

rest i guess is clear.......read your books properly...this is given in any c++ book..........

In function decleration you need to specify return type of the function(you were missing that).....only constructors and destructors don't have return type....rest all the member function should have a return type
Reply With Quote Quick reply to this message  
•
•
Join Date: Sep 2004
Posts: 421
Reputation: JoBe is on a distinguished road 
Solved Threads: 4
JoBe's Avatar
JoBe JoBe is offline Offline
Posting Pro in Training

Re: Adding memberfunctions into a class?

 
0
  #5
Nov 5th, 2005
Doh, how stupid I have been :o
Reply With Quote Quick reply to this message  
Reply

Quick Reply to Thread
This thread is more than three months old.
Perhaps start a new thread instead?
•
•
•
•
•
•
•
•
Message:
•
•
•
•



Similar Threads
Other Threads in the C++ Forum
Thread Tools Search this Thread



api array based binary c++ c/c++ calculator char char* class classes code coding compile console conversion count database delete deploy desktop developer directshow dll download dynamic dynamiccharacterarray email encryption error file forms fstream function functions game givemetehcodez google graph gui homeworkhelp iamthwee ifstream input int integer java lib linkedlist linker linux list loop looping loops map math matrix memory multiple news number numbertoword output parameter pointer problem program programming project python random read recursion recursive reference return rpg sorting string strings struct temperature template templates test text text-file tree unix url variable vector video visualstudio win32 windows winsock wordfrequency wxwidgets
About Us | Contact Us | Advertise | DaniWeb | Acceptable Use Policy | RSS Feed

©2003 - 2009 DaniWeb® LLC