array 2d dynamic allocation c++

To dynamically allocate a 2D array in C++, follow these steps:

1. Declare the necessary variables: You will need variables to hold the number of rows and columns in the array, as well as a pointer to the array itself. For example:

cpp int numRows, numCols; int array;

1. Prompt the user for the desired number of rows and columns, and store the values in the corresponding variables. For example:

```cpp cout << "Enter the number of rows: "; cin >> numRows;

cout << "Enter the number of columns: "; cin >> numCols; ```

1. Allocate memory for the array using the new operator. Since this is a 2D array, you will need to allocate memory for each row and then assign the addresses of those rows to the main pointer. For example:

```cpp array = new int*[numRows]; // Allocate memory for rows

for (int i = 0; i < numRows; i++) { array[i] = new int[numCols]; // Allocate memory for each column in the row } ```

1. You can now access and manipulate the elements of the dynamically allocated 2D array using the usual array notation. For example, to assign a value to an element at row i and column j:

cpp array[i][j] = value;

1. Don't forget to deallocate the memory used by the array when you're done with it. Start by deallocating memory for each row, and then deallocate the main pointer. For example:

```cpp for (int i = 0; i < numRows; i++) { delete[] array[i]; // Deallocate memory for each column in the row }

delete[] array; // Deallocate memory for rows ```

This is the basic process for dynamically allocating a 2D array in C++. Make sure to handle any error conditions that may arise during memory allocation, and always deallocate the memory when you're finished to avoid memory leaks.