Ranged for loop with arrays of arrays

[jakvrh1]

        int arr[4][5];

	for (int(&row)[5] : arr){
		for (int &column : row){

		}
	}

Why do we name it row instead column? int arr[row][column]
Wouldn't this be like

int arr[4][5];

	for (int(&column)[5] : arr){
		for (int &row: column){

		}

It just seems funny to me because we use row[5] which should be 4 if we meant row? Or did I read it wrong in C++ prime !?

[Peter87]

You can of course call it whatever you want but if you use the convention array[rows][columns], then arr[1] gives you the second row, and when you do do row[3] you get the value of the fourth column of the row.

[Duthomhas]

int m[3][4] =
{
  { 1,  2,  3,  4 },  // row 0
  { 5,  6,  7,  8 },  // row 1
  { 9, 10, 11, 12 }   // row 2
};

The array m has 3 rows and 4 columns.

If I want to access the element at the second row (row 1) and the third column (column 2), then I would write m[1][2].

If I want to access an entire row, I do it easily: m[1] → {5,6,7,8}.

This makes it difficult to access data by columns, but it proves to be less problematic than you would think. (There are numerous ways around it.)

Hope this helps.