Question

Cannot figure out why my c++ program keeps crashing, I am attempting to have the user decide the size of a 2d array then fill said array.

#include <iostream>

using namespace std;

typedef int* IntArrayPtr;

int main(void)

{

int column, row, i, j;

IntArrayPtr *arr_num = new IntArrayPtr[row];

cout << " " << endl

<< " This program creates a 2D array of dynamic memory, fills it with user entered numbers, " << endl

<< " Then prints the array to the screen. " << endl

<< " " << endl

<< " Enter the column dimensions of the array. " << endl

<< " " << endl;

cin >> column;

cout << " " << endl

<< " Enter the row dimensions of the array. " << endl

<< " " << endl;

cin >> row;

// This loop allocates dynamic memory for a 2D array of intigers.

// arr_num is now a 2dD array of dynamic memory and is of the size entered by the user.

for (i = 0; i < column; i++)

{

arr_num[i] = new int[column];

}

cout << " " << endl

<< " Enter " << column << " sets of " << row << " whole numbers. " << endl

<< " " << endl;

for (i = 0; i < column; i++)

{

for (j = 0; j < row; j++)

{

cin >> arr_num[i][j];

}

}

cout << " " << endl

<< " Now to display the 2D array of numbers entered. " << endl

<< " " << endl;

for (i = 0; i < column; i++)

{

for (j = 0; j < row; j++)

{

cout << arr_num[i][j] << " ";

cout << endl;

}

}

for (i = 0; i < column; i++)

{

delete[] arr_num[i];

}

delete[] arr_num;

return 0;

}

Answer 1

Its working properly I have tested it properly

#include <iostream>

using namespace std;

typedef int* IntArrayPtr;

int main(void)

{

int column, row, i, j;

IntArrayPtr *arr_num = new IntArrayPtr[row];

cout << " " << endl

<< " This program creates a 2D array of dynamic memory, fills it with user entered numbers, " << endl

<< " Then prints the array to the screen. " << endl

<< " " << endl

<< " Enter the column dimensions of the array. " << endl

<< " " << endl;

cin >> column;

cout << " " << endl

<< " Enter the row dimensions of the array. " << endl

<< " " << endl;

cin >> row;

// This loop allocates dynamic memory for a 2D array of intigers.

// arr_num is now a 2dD array of dynamic memory and is of the size entered by the user.

for (i = 0; i < column; i++)

{

arr_num[i] = new int[column];

}

cout << " " << endl

<< " Enter " << column << " sets of " << row << " whole numbers. " << endl

<< " " << endl;

for (i = 0; i < column; i++)

{

for (j = 0; j < row; j++)

{

cin >> arr_num[i][j];

}

}

cout << " " << endl

<< " Now to display the 2D array of numbers entered. " << endl

<< " " << endl;

for (i = 0; i < column; i++)

{

for (j = 0; j < row; j++)

{

cout << arr_num[i][j] << " ";

}
cout << endl;
}

for (i = 0; i < column; i++)

{

delete[] arr_num[i];

}

delete[] arr_num;

return 0;

}

Please comment below if you have any issues