Jun 2, 2009 · std array behaves like normal array in c++, that you define with pointer, for example int* and then: new int[size], or without pointer: int arr[size], but unlike the normal array of the c++, std array provides functions that you can use with the elements of the array, like fill, begin, end, size, and etc, but normal array provides nothing.

Oct 11, 2012 · To declare a 2D array using std::vector, you can use this kind of construction: vector<vector<int> > matrix( n, vector<int>(m, -1) ); This creates a 2D array matrix of size n by m, with all elements initialised to -1. It's basically a nesting of …

The following is a 2D array that can be called an array of arrays: int AoA[10][10]; The following is a pointer to a pointer that has been set up to function as a 2D array:

Mar 14, 2012 · This will initialize a 2D vector of rows=row and columns = col with all initial values as 0. No need to initialize and use resize. Since the vector is initialized with size, you can use "[]" operator as in array to modify the vector. matrix[x][y] = 2;

The first method cannot be used to create dynamic 2D arrays because by doing:. int *board[4]; you essentially allocated an array of 4 pointers to int on stack.

Jan 7, 2012 · Although int array[][10] is allowed, I'd not recommend it over the above syntax since the above syntax makes it clear that the identifier array is a single pointer to an array of 10 integers, while this syntax looks like it's a 2D array but is the same pointer to an array of 10 integers. Here we know the number of elements in a single row (i.e ...

May 13, 2020 · Initialising 2d array using 1 d array in c++. 2. Initialize 2d array in Class. 0. 2-dimensional array ...

Jun 7, 2013 · Well, it depends on the use case. If the number of elements is small, a vector of vectors could have a significant size overhead over, say, a plain 2D array of contiguous elements. But one would first have to make sure this is actually an issue. The best approach is to abstract the storage away inside a 2D array class. –

Apr 8, 2012 · But, generally, for further info I recommend you to try Google first with questions like "2D array in C++" or "dynamic allocation of 2D array C++", i. e. this query. Share Improve this answer

Oct 11, 2010 · I suggest using a far simpler method than an array of arrays: #define WIDTH 3 #define HEIGHT 4 int* array = new int[WIDTH*HEIGHT]; int x=1, y=2, cell; cell = array[x+WIDTH*y]; I think this is a better approach than an array of an array, as there is far less allocation. You could even write a helper macro: