C++ Multidimensional Arrays

A multidimensional array in C++ is an array that has more than one dimension. The most common form of multidimensional arrays are two-dimensional arrays, but you can have arrays with more dimensions (3D, 4D, etc.).

Multidimensional arrays can be described as “arrays of arrays”. For example, a bidimensional array can be imagined as a bidimensional table made of elements, all of them of a same uniform data type.

Two-Dimensional Array (2D Array)

A two-dimensional array can be thought of as an array of arrays. It’s often used to represent tables, grids, or matrices.

Syntax:


type arrayName[rowSize][columnSize];

Explanation:

rowSize represents the number of rows
columnSize represents the number of columns.

Example:


#include <iostream>
using namespace std;

int main() {
    // Declare a 2D array with 2 rows and 3 columns
    int arr[2][3] = {
        {1, 2, 3},
        {4, 5, 6}
    };

    // Accessing and printing elements of the 2D array
    for (int i = 0; i < 2; i++) {          // Loop through rows
        for (int j = 0; j < 3; j++) {      // Loop through columns
            cout << arr[i][j] << " ";
        }
        cout << endl;  // New line after each row
    }

    return 0;
}

Explanation:

int arr[2][3]: This declares a 2D array with 2 rows and 3 columns.
arr[i][j]: This accesses the element at the i-th row and j-th column.

Output:

1 2 3
4 5 6

C++ Multidimensional Arrays – Interview Questions

Q 1: What is a multidimensional array?

Ans: An array with more than one dimension, like 2D or 3D arrays.

Q 2: How do you declare a 2D array?

Ans: int arr[3][3];

Q 3: How are elements accessed in 2D arrays?

Ans: Using row and column index: arr[i][j].

Q 4: Where are multidimensional arrays stored?

Ans: In contiguous memory (row-major order).

Q 5: What is a common use case?

Ans: Representing matrices or tables.