How to iterate a Multidimensional Array?

Multidimensional arrays are arrays that have more than one dimension. For example, a simple array is a 1-D array, a matrix is a 2-D array, and a cube or cuboid is a 3-D array but how to visualize arrays with more than 3 dimensions, and how to iterate over elements of these arrays? It is simple, just think of any multidimensional array as a collection of arrays of lower dimensions.

n-D array = Collection of (n-1)D arrays 

For example, a matrix or 2-D array is a collection of 1-D arrays.

2D Array is a collection of 1D Arrays

Similarly, you can visualize 3-D arrays and other multidimensional arrays.

How to iterate over elements of a Multidimensional array? 

It can be observed that only a 1-D array contains elements and a multidimensional array contains smaller dimension arrays.

•  Hence first iterate over the smaller dimension array and iterate over the 1-D array inside it. 
• Doing this for the whole multidimensional array will iterate over all elements of the multidimensional array.

Example 1: Iterating over a 2-D array

C++

#include <bits/stdc++.h>
using namespace std;

int main()
{
    // Considering 2-D array having 3 rows and 3 columns
    int n = 3;
    int m = 3;
    int arr[][3]
        = { { 3, 2, 7 }, { 2, 6, 8 }, { 5, 1, 9 } };

    // Iterating over all 1-D arrays in 2-D array
    for (int i = 0; i < n; i++) {

        // Printing all elements in ith 1-D array
        for (int j = 0; j < m; j++) {

            // Printing jth element of ith row
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }
    return 0;
}

Java

// Java Code for iterating over a 2D array.

import java.io.*;

class GFG {
    public static void main(String[] args)
    {
        int n = 3;
        int m = 3;
        int[][] arr
            = { { 3, 2, 7 }, { 2, 6, 8 }, { 5, 1, 9 } };

        // Iterating over all 1-D arrays in 2-D array
        for (int i = 0; i < n; i++) {
            // Printing all elements of ith row
            for (int j = 0; j < m; j++) {
                System.out.print(arr[i][j] + " ");
            }
            System.out.println();
        }
    }
}

// This code is contributed by lokeshmvs21.

Python3

# python code to implement the approach

if __name__ == "__main__":

    # Considering 2-D array having 3 rows and 3 columns
    n = 3
    m = 3
    arr = [[3, 2, 7], [2, 6, 8], [5, 1, 9]]

    # Iterating over all 1-D arrays in 2-D array
    for i in range(0, n):

        # Printing all elements in ith 1-D array
        for j in range(0, m):

            # Printing jth element of ith row
            print(arr[i][j], end=" ")

        print()

    # This code is contributed by rakeshsahni

C#

using System;

public class GFG{

  static public void Main (){

    // Code
    int n = 3;
    int m = 3;
    int [ , ] arr = { { 3, 2, 7 }, { 2, 6, 8 }, { 5, 1, 9 } };

    // Iterating over all 1-D arrays in 2-D array
    for (int i = 0; i < n; i++) {

      // Printing all elements in ith 1-D array
      for (int j = 0; j < m; j++) {

        // Printing jth element of ith row
        Console.Write(arr[i,j]);
        Console.Write(" ");
      }
      Console.Write("\n");
    }

  }
}

// This code is contributed by akashish_.

Javascript

<script>

    // Considering 2-D array having 3 rows and 3 columns
    let n = 3;
    let m = 3;
    let arr
        = [[ 3, 2, 7 ], [ 2, 6, 8 ], [ 5, 1, 9 ] ];

    // Iterating over all 1-D arrays in 2-D array
    for (let i = 0; i < n; i++) {

        // Printing all elements in ith 1-D array
        for (let j = 0; j < m; j++) {

            // Printing jth element of ith row
           document.write(arr[i][j] + " ");
        }
        document.write("<br>");
    }

    // This code is contributed by satwik4409.
    </script>

Output

3 2 7 
2 6 8 
5 1 9 

Time Complexity: O(n*m)
Auxiliary Space: O(1)

Example 2: Iterating over a 3D array

C++

#include <bits/stdc++.h>
using namespace std;

// Driver code
int main()
{
    // Consider 3-D array of dimensions 2*2*2
    int x = 2, y = 2, z = 2;
    int arr[][3][2] = { { { 1, 2 }, { 3, 4 } },
                        { { 5, 6 }, { 7, 8 } } };

    // Iterating over each 2-D array in 3-D array
    for (int i = 0; i < x; i++) {
        cout << "Inside " << i + 1
             << " 2D array in 3-D array" << endl;

        // Iterating over each 1-D array
        for (int j = 0; j < y; j++) {
            cout << "Inside " << j + 1
                 << " 1D array of the 2-D array" << endl;

            // Iterating over each element in 1-D array
            for (int k = 0; k < z; k++) {
                cout << arr[i][j][k] << " ";
            }
            cout << endl;
        }
        cout << endl;
    }
    return 0;
}

Java

// Java Program for iterating over a 3D array.

import java.io.*;

class GFG {
    public static void main(String[] args)
    {
        // Consider 3-D array of dimensions 2*2*2
        int x = 2, y = 2, z = 2;
        int[][][] arr = { { { 1, 2 }, { 3, 4 } },
                          { { 5, 6 }, { 7, 8 } } };

        // Iterating over each 2-D array in 3-D array
        for (int i = 0; i < x; i++) {
            System.out.println("Inside " + (i + 1)
                             + " 2D array in 3D array");

            // Iterating over each 1-D array
            for (int j = 0; j < y; j++) {
                System.out.println(
                    "Inside" + (j + 1)
                    + " 1D array of the 2D array");

                // Iterating over each element in 1-D array
                for (int k = 0; k < z; k++) {
                    System.out.print(arr[i][j][k] + " ");
                }
                System.out.println();
            }
            System.out.println();
        }
    }
}

// This code is contributed by lokeshmvs21.

Python3

# Python code
 # Consider 3-D array of dimensions 2*2*2
x = 2
y = 2
z = 2
arr = [ [ [ 1, 2 ], [ 3, 4 ] ],[ [ 5, 6 ], [ 7, 8 ] ] ]

# Iterating over each 2-D array in 3-D array
for i in range(0,x):
  print("Inside " + str(i + 1) + " 2D array in 3-D array")

  # Iterating over each 1-D array
  for j in range(0,x):
    print("Inside " + str(j + 1) + " 1D array of the 2-D array")

    # Iterating over each element in 1-D array
    for k in range(0,x):
      print(arr[i][j][k],end=" ")
    print("")

  print("")

  # This code is contributed by akashish__

C#

// C# Program for the iterating over a 3D array.

using System;

public class GFG {

    static public void Main()
    {

        // Code
        // Consider 3-D array of dimensions 2*2*2
        int x = 2, y = 2, z = 2;
        int[, , ] arr
            = new int[2, 2, 2] { { { 1, 2 }, { 3, 4 } },
                                 { { 5, 6 }, { 7, 8 } } };

        // Iterating over each 2-D array in 3-D array
        for (int i = 0; i < x; i++) {
            Console.Write("Inside " + (i + 1)
                          + " 2D array in 3D array"
                          + "\n");

            // Iterating over each 1-D array
            for (int j = 0; j < y; j++) {
                Console.Write("Inside" + (j + 1)
                              + " 1D array of the 2D array"
                              + "\n");

                // Iterating over each element in 1-D array
                for (int k = 0; k < z; k++) {
                    Console.Write(arr[i, j, k] + " ");
                }
                Console.Write("\n");
            }
            Console.Write("\n");
        }
    }
}

// This code is contributed by lokeshmvs21.

Javascript

<script>
// Driver code

    // Consider 3-D array of dimensions 2*2*2
    let x = 2;
    let  y = 2;
    let  z = 2;
    let arr = [ [ [1, 2 ], [ 3, 4 ] ],
                        [ [ 5, 6 ], [ 7, 8 ] ] ];

    // Iterating over each 2-D array in 3-D array
    for (let i = 0; i < x; i++) {
         document.write( "Inside " + (i + 1)
             + " 2D array in 3-D array" );
        document.write("<br>");

        // Iterating over each 1-D array
        for (let j = 0; j < y; j++) {
            document.write( "Inside " + (j + 1)
              +" 1D array of the 2-D array" );
               document.write("<br>");

            // Iterating over each element in 1-D array
            for (let k = 0; k < z; k++) {
                 document.write( arr[i][j][k] + " ");
            }
           document.write("<br>");
        }
        document.write("<br>");
    }

    // This code is contributed by satwik4409.
    </script>

Output

Inside 1 2D array in 3-D array
Inside 1 1D array of the 2-D array
1 2 
Inside 2 1D array of the 2-D array
3 4 

Inside 2 2D array in 3-D array
Inside 1 1D array of the 2-D array
5 6 
Inside 2 1D array of the 2-D array
7 8 

Time Complexity: O(x*y*z)
Auxiliary Space: O(1)