How to iterate a Multidimensional Array? (original) (raw)
Last Updated : 07 Nov, 2022
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 rakeshsahniC#
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
`
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 222 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 222 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 222
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
`
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)