Need some help with C++ object oriented programing

akairyuu · 09-25-2009, 02:09 AM

k so heres my problem im writing a program that has a class called String and this will take a string and remove the null charicter and it will have a varible for the length of the string.

im using Dev C++ as a compiler, yeah probly not the best but its free.

the errors im getting are when i start to overload ostream.
heres what the compiler says:

11 main.cpp In file included from main.cpp
121 My_String.h ISO C++ forbids declaration of `ostream' with no type
121 My_String.h `ostream' is neither function nor member function;
cannot be declared friend
121 My_String.h expected `;' before '&' token
125 My_String.h ISO C++ forbids declaration of `istream' with no type
125 My_String.h `istream' is neither function nor member function;
cannot be declared friend
125 My_String.h expected `;' before '&' token
G:\CISP 430\Project2\Makefile.win [Build Error] [main.o] Error 1

and now the main part of the code
first the .h file

Code:

class String
{
    
    char* STR; //string
    unsigned Len; // length of string
    
public
    friend ostream& operator<< (ostream& , const String&);

    friend istream& operator>> (istream& , const String&);

now the .cpp file

Code:

ostream& operator<<(ostream& Os, const String& s)
{
    for(unsigned I=0; I < s.Len;I++)
    {
        Os<<s[i];
    }
    return (Os);
}

istream& operator>>(istream& Is, const String& s )
{
    String Temp;
    char cc;
    while (is.get(cc))
    {
        if (cc=='\n')
        {
            break;
        }
    }
    Temp +=cc;
    s = Temp;
    return Is;
}

**CornedBee** · 09-25-2009, 02:57 AM

You're not including the standard headers for istream and ostream, and/or not getting them into the correct scope.

What tutorial are you going by? This code has many other errors, too.

akairyuu · 09-26-2009, 02:30 AM

well thats not all my code. but just to make sure i have all the right headers in my files here they are these are just the headers in each file.

Main.cpp

Code:

#include <cstdlib>
#include <iostream>
#include "My_String.h"

using namespace std;

My_String.cpp

Code:

#include <cstdlib>
#include <iostream>
#include "My_String.h"

using namespace std;

My_String.h

Code:

#include <iostream>

using namespace std;

and if you would like to see all code just let me know
thank you.

09-25-2009, 02:09 AM	#1
akairyuu Registered User Join Date: Sep 2009 Location: california Posts: 7	Need some help with C++ object oriented programing k so heres my problem im writing a program that has a class called String and this will take a string and remove the null charicter and it will have a varible for the length of the string. im using Dev C++ as a compiler, yeah probly not the best but its free. the errors im getting are when i start to overload ostream. heres what the compiler says: 11 main.cpp In file included from main.cpp 121 My_String.h ISO C++ forbids declaration of `ostream' with no type 121 My_String.h `ostream' is neither function nor member function; cannot be declared friend 121 My_String.h expected `;' before '&' token 125 My_String.h ISO C++ forbids declaration of `istream' with no type 125 My_String.h `istream' is neither function nor member function; cannot be declared friend 125 My_String.h expected `;' before '&' token G:\CISP 430\Project2\Makefile.win [Build Error] [main.o] Error 1 and now the main part of the code first the .h file Code: class String { char* STR; //string unsigned Len; // length of string public friend ostream& operator<< (ostream& , const String&); friend istream& operator>> (istream& , const String&); now the .cpp file Code: ostream& operator<<(ostream& Os, const String& s) { for(unsigned I=0; I < s.Len;I++) { Os<<s[i]; } return (Os); } istream& operator>>(istream& Is, const String& s ) { String Temp; char cc; while (is.get(cc)) { if (cc=='\n') { break; } } Temp +=cc; s = Temp; return Is; }
akairyuu is offline

09-25-2009, 02:57 AM	#2
CornedBee Cat without Hat Join Date: Apr 2003 Posts: 8,439	You're not including the standard headers for istream and ostream, and/or not getting them into the correct scope. What tutorial are you going by? This code has many other errors, too. __________________ All the buzzt! CornedBee "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code." - Flon's Law
CornedBee is offline

09-26-2009, 02:30 AM	#3
akairyuu Registered User Join Date: Sep 2009 Location: california Posts: 7	well thats not all my code. but just to make sure i have all the right headers in my files here they are these are just the headers in each file. Main.cpp Code: #include <cstdlib> #include <iostream> #include "My_String.h" using namespace std; My_String.cpp Code: #include <cstdlib> #include <iostream> #include "My_String.h" using namespace std; My_String.h Code: #include <iostream> using namespace std; and if you would like to see all code just let me know thank you. Last edited by akairyuu; 09-26-2009 at 02:45 AM. Reason: for got code
akairyuu is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
What's a good Object Oriented Strategy for OpenGL/Graphics	indigo0086	Game Programming	9	04-03-2007 06:27 PM
object oriented C	FlatLost	C Programming	4	11-08-2005 06:22 AM
Question on l-values.	Hulag	C++ Programming	6	10-13-2005 04:33 PM
A question about constructors...	Wolve	C++ Programming	9	05-04-2005 04:24 PM