How properly dynamically allocate 2d array inside void function? - c++

Question

I 'm still newbie in C++, so don't be mean to me. I would like to know how to initialize 2 dimentional array in the void function.
This is my example code but it gives me exceptions about access violation locations instead:
#include "stdafx.h"
void matrixInit(char***);
void matrixDel(char**);
void main(void){
char** game=0;
matrixInit(&game);
matrixDel(game);
return;
}
void matrixInit(char*** matrix) {
matrix = new char**[3];
for (int i(0); i < 3; i++) {
matrix[i] = new char*[3];
for (int j(0); j < 3; j++)
*matrix[i][j] = '0';
}
return;
}
void matrixDel(char** matrix) {
for (int i(0); i < 3; i++)
delete[] matrix[i];
delete[] *matrix;
return;
}

Answer 1

Props to #fireant for the help with allocating the array. After some research and debugger plays, I figure all it out. I hope this solution will help someone in the future!
#include "stdafx.h"
using namespace std;
int** matrixInit(int, int);
void matrixInit(int***, int, int);
void matrixDel(int**, int);
void matrixFill(int**, int, int);
void matrixPrint(int**, int, int);
void main(void) {
const int rows = 3, cols = 3;
int** game;
matrixInit(&game, rows, cols); //Void allocation
//game = matrixInit(rows, cols); //Alternative allocation
matrixFill(game, rows, cols);
matrixPrint(game, rows, cols);
matrixDel(game, rows);
cout << endl << "Passed!"; //<iostream> lib required
_getch(); //<conio.h> lib required
return;
}
//Dynamical array allocation void function
void matrixInit(int*** matrix, int nRow, int nColumn) {
(*matrix) = new int*[nRow];
for (int i(0); i < nRow; i++)
(*matrix)[i] = new int[nColumn];
}
//Dynamical array allocation pointer return function
int** matrixInit(int nRow, int nColumn) {
int** matrix = new int*[nRow];
for (int i(0); i < nRow; i++)
matrix[i] = new int[nColumn];
return matrix;
}
//Dynamical array deallocation void function
void matrixDel(int** matrix, int nRow) {
for (int i(0); i < nRow; i++)
delete[] matrix[i];
delete[] matrix;
}
//Fill array void function
void matrixFill(int** matrix, int nRow, int nColumn) {
for (int i(0); i < nRow; i++)
for (int j(0); j < nColumn; j++)
matrix[i][j] = (j + 1) + (i * nRow);
}
//Print array void function
void matrixPrint(int** matrix, int nRow, int nColumn) {
for (int i(0); i < nRow; i++)
for (int j(0); j < nColumn; j++)
cout << "[" << i << "][" << j << "] = " << matrix[i][j] << endl;
}

Answer 2

You're almost there,
void matrixInit(char*** matrix) {
(*matrix) = new char*[3];
for (int i(0); i < 3; i++) {
(*matrix)[i] = new char[3];
for (int j(0); j < 3; j++)
(*matrix)[i][j] = '0';
}
return;
}
You're passing the address matrixInit(&game), but matrix = new char**[3]; is overwriting the passed address. Thus, game in main is not pointing to the allocated memory. You could have written void matrixInit(char*** const matrix) to make sure you don't change the address accidentally inside the function. As a practice try to fix your delete function.