undeclared variable...

[nickyeng]

i have 2 following files.
I compiled it with g++ in cygwin.
i get errors.

here is my 2 files.

/* array2d.h  */
#ifndef _ARRAY2D_H_
#define _ARRAY2D_H_
#include "exception.h"
 
namespace Game {
 
    /*** Simple template class for a 2D Array ***/
    template<class T>
    class Array2D {
    public:
        Array2D(unsigned width, unsigned height) : xsize(width), ysize(height) {
            array = new T[xsize * ysize];
        }
        ~Array2D() { delete array; }
        void Put(unsigned x, unsigned y, T item) {
            if (x >= xsize || y >= ysize) {
                throw GameException("Array out of bounds");
            }
            array[y * xsize + x] = item;
        }
        T Get(unsigned x, unsigned y) const {
            if (x >= xsize || y >= ysize) {
                throw GameException("Array out of bounds");
            }
            return array[y * xsize + x];
        }
        void SetAll(T item) {
            for (unsigned i = 0; i < xsize * ysize; i++) {
                array[i] = item;
            }
        }
    private:
        const unsigned xsize;
        const unsigned ysize;
        T* array;
    };
}
#endif
 

/* screen.h */
#ifndef _SCREEN_H_
#define _SCREEN_H_
#include <string>
#include <iostream>
#include <fstream>
#include "array2d.h"
 
namespace Game{
    using namespace std;
 
    class Screen{
        public:
        Screen(){
            Xsize = 80;
            Ysize = 23;
            Array2D <char> myArray(Xsize,Ysize);
        };
 
        ~Screen(){}
 
        /*
        Insert a character into the screen image at a specified row and column.
        */
        void Insert(){
            char c = 'H';
            myArray.Put(68, 23,c);
        }
 
        void setStatus(string str){
            status = str;
        }
 
        /* clear the previous screen and display new screen image with Xsize Ysize */
        void Paint(){
            /* clear the screen image */
            system("clear");
            cout << myArray.Get(Xsize , Ysize);
        }
 
        /* display the help.txt and allow   */
        int displayHelp(){
            char c;
            char text;
            ifstream in("help.txt");
 
            system("stty raw -echo");
            cin.get(c);
            system("stty raw -echo");
 
            if(c == 'h' || c == 'H')
            {
                if(!in){
                    cout << "Unable to open help.txt file" << endl;
                    return 1;
                }
 
                while(in >> text){
                    myArray.Put(Xsize, Ysize, text);
                }
            }
        }
        private:
        unsigned Xsize;
        unsigned Ysize;
        string status;
    };
}
#endif
 

I compiled using above exactly same code together, i get this error:

i thought it was the Array2D initialization issue, so i initialise it under "private" section as following:

Array2D <char> myArray;
 

Still, i get another error :

Please tell me where should change the code about the Array2D ...?
thanks in advance.
Nicky Eng

[nickyeng]

Note: I cannot change the code in array2d.h header file, what can be change is only within screen.h header file.

thanks.

[DeMan]

becauss myArray is declared inside a method, it's scope is limited to that method. When the compiler comes accross the variable in another method, as far as it is concerned, this is another (different) variable.

Possible solutions to this woudl be to pass it through the methods, or to declare it outside the methods so that it is visible to the entire class.

[nickyeng]

becauss myArray is declared inside a method, it's scope is limited to that method. When the compiler comes accross the variable in another method, as far as it is concerned, this is another (different) variable.

Possible solutions to this woudl be to pass it through the methods, or to declare it outside the methods so that it is visible to the entire class.

I tried it already.
I put

Array2D<char> myArray;
 

under "public:" , and then i put "myArray(Xsize,Ysize);" inside constructor.

it give me the 2nd error (post number 1 printscreen error image 2).

[horace1]

I tried it already.
I put

Array2D<char> myArray;
 

under "public:" , and then i put "myArray(Xsize,Ysize);" inside constructor.

it give me the 2nd error (post number 1 printscreen error image 2).

think in the constructor you need to have Xsize, Ysize and myArray in an initialisation list, e.g.

    Screen(): Xsize(80) , Ysize (23), myArray (Xsize,Ysize){};
    ~Screen(){}
 

and put myArray under private:

        private:
        unsigned Xsize;
        unsigned Ysize;
        Array2D <char> myArray;
        string status;
 

[DeMan]

<removed>
Sorry, as always I was beaten whilst I typed

[nickyeng]

thank you Horace1.

it helped.

thanks again.
:D

Screen(): Xsize(80) , Ysize (23), myArray (Xsize,Ysize){};
 

This is made me confused.
I have to get learn of it.

NickyEng.