Multidimensional Arrays

Multidimensional Arrays

An array whose elements are themselves arrays forms a grid: rows and columns.

A 2D array

string letters[2][3] = {
    {"A", "B", "C"},
    {"E", "F", "G"}
};

• The first index picks the row.
• The second index picks the column.

cout << letters[0][1];   // B   (row 0, column 1)
cout << letters[1][2];   // G   (row 1, column 2)

Nested loops

To visit every cell, use a loop inside another loop - one for the rows, one for the columns:

for (int r = 0; r < 2; r++) {
    for (int c = 0; c < 3; c++) {
        cout << letters[r][c];
    }
}

That prints ABCEFG, walking each row from left to right.

More dimensions

Add another index for another dimension: int cube[2][3][4]; is a 2x3x4 block of ints. The pattern is the same - one nested loop per dimension.

TL;DR

• A 2D array is an array of arrays - a grid with rows and columns.
• First index = row; second index = column.
• letters[1][2] reaches index row 1, column 2.
• Walk all cells with nested loops.
• Each additional dimension adds one more index and one more loop.