heap error

vagelis (106)
i get this error at the beginining of run the project
"Windows has triggered a breakpoint in diplomatiki_me_arrays.exe.

This may be due to a corruption of the heap, and indicates a bug in diplomatiki_me_arrays.exe or any of the DLLs it has loaded."



i use the following class and when in delete(~Array2d) i change lengthrow with sizerow it runs but stops after many many calculations(it is a simulation)

any idea??



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template <typename T>
struct Array2D
{
private : int lengthrow ,lengthcolumn;// -> max_rows
		  int multiply;

public  : T **Data ;
		  int sizerow,sizecolumn; //   -> rows


		  Array2D() // contructors
		  {
			  lengthrow   = 10;
			  lengthcolumn = 10;
			  multiply = 2; 

			  Data = new T*[lengthrow];
			  for (int i=0;i<lengthrow;i++)
			  {
				  Data[i] = new T[lengthcolumn];
			  }

			  sizerow = 0;
			  sizecolumn =0;
		  }

		  Array2D(int lengrow,int lengcol) // contructors
		  {
			  lengthrow   = lengrow;
			  lengthcolumn= lengcol;
			  multiply = 2; 

			  Data = new T*[lengthrow];
			  for (int i=0;i<lengthrow;i++)
			  {
				  Data[i] = new T[lengthcolumn];
			  }

			  sizerow = 0;
			  sizecolumn=0;
		  }



	/*	  T* operator[](int index) 
		  {
			  return Data[index]; 
		  }
*/


		  Array2D (const Array2D &a) //copy constructor.
		  {
			  lengthrow   = a.lengthrow;
			  lengthcolumn   = a.lengthcolumn;
			  multiply = a.multiply; 
			  sizerow = a.sizerow;
			  sizecolumn = a.sizecolumn;
			  Data = new T *[lengthrow];
			  for (int i=0;i<lengthrow;i++)
			  {
				  Data[i] = new T[lengthcolumn];
			  }
		
			  for(int i=0;i<a.sizerow;i++)
				  for(int j=0; j < a.sizecolumn ; j++)
					  Data[i][j]=a.Data[i][j];
		  }


		  ~Array2D()
		  {
			  if (Data)
			  {
				  for(int i=0;i<lengthrow;i++) delete [] Data[i]; 
				  delete [] Data;
				  Data = NULL;
			  }

			  sizerow =0;
			  sizecolumn=0;
			  
		  }




		  Array2D<T>& operator = (Array2D <T> &a) 
		  { 
			  if (this == &a) return *this;
			  if (a.sizerow > lengthrow)
			  {
				  lengthrow = a.lengthrow;
				  lengthcolumn = a.lengthcolumn;
				  multiply = a.multiply;
				 
				  for(int i=0;i<lengthrow;i++) delete [] Data[i]; 
				  delete [] Data;
				  Data = new T*[lengthrow];
				  for (int i=0;i<lengthrow;i++)
				  {
					  Data[i] = new T[lengthcolumn];
				  }

			  }
			   
				sizerow = a.sizerow;
			  sizecolumn = a.sizecolumn;
			  for(int i=0;i<a.sizerow;i++)
				  for(int j=0;j<a.sizecolumn;j++)
				  {
					  Data[i][j]=a.Data[i][j];
				  }


			  //copy(a.Data, a.Data + a.lengthrow  , Data); 

			  return *this;
		  }
};
Last edited on
PanGalactic (1658)
In your assignment operator, you change lengthrow before you loop through your array to delete the existing elements.
vagelis (106)
this is correct what you say but it doesnt make difference..
it must be another problem that causes this error
kbw (9488)
Why is Data public? Any part of the program can corrupt it without detection. The whole point of information hiding is to prevent these difficult to solve problems.

Make Data private, provide get/set methods with range checking.
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