How do I declare a 2D array in C++ using new [Reopened]? [duplicate]

Question

I have already seen :

How do I declare a 2d array in C++ using new?

But none of the answer seems to answer the question "How to declare a ** 2D array using new ** ?"

All the answers seems to show alternatives either by declaring array of pointers or by declaring row*column sized single dimensional array and then using row, column calculations explicitly.

But is there any way to directly allocate a 2D array in the heap in c++ just in the same way we do in the stack?

Example :

int stackarray[3][2];

//Is there some equivalent to above?? Like :

= new int[3][2];

Answer 1

But is there any way to directly allocate a 2D array in the heap in c++ just in the same way we do in the stack?

Yes.

Method 1 (C++11 or higher)

auto arr = new int[3][2];

Method 2

int (*arr)[2] = new int[3][2];

arr is a pointer to int [2], i.e. an array of 2 ints. With that allocation, the valid indices to access the elements of the 2D array are arr[0][0] -- arr[2][1]

Method 3

typedef int ARRAY1[2];
ARRAY1* arr = new ARRAY1[3];

or if using C++11 or higher,

using ARRAY1 = int[2];
ARRAY1* arr = new ARRAY1[3];