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In this post, we're gonna learn about Multi-dimensional arrays in

  • Python,
  • C#,
  • Java.

Before we begin, let's see the part one that we talk about a one-dimensional array

Multidimensional array:-

  • is an array with more than one dimension it can be two , three,...Nth dimension.
  • size of the array  can be calculated as the total number of elements that can be stored in a multi-dimensional array can be calculated by multiplying the size of all the dimensions

What is a two-dimensional array?

  • A two-dimensional array is the simplest form of multi=dimensional array
  • A two-dimensional array is a two-dimensional series represented by rows and columns.
  • It is used to store information in a matrix "in a tabular form".
  • It can be defined as an array of arrays. 

How can we access the two-dimensional array elements?

  • Each element in the two-dimensional array has row index and column index, it is accessed by these indices.
  • Both row-index and column-index start at 0.

Two-dimensional Arrays in C#

  • C# support multi-dimensional arrays, we will talk about the two-dimensional form.
  • It is accessed by using the two indices.
  • Both row-index and column-index start at 0.
  • the two-dimensional is declared with [ , ] after the data type.

Two-dimensional array declaration in C#

datatype[ ,] arrayName;
  • Data Type  : It defines the element type of the array.
  • [ , ] : It defines the size of the array depending on row and column indices;
  • arrayName: It is the Name of array
  • the three-dimensional declared with [ , , ] ...etc.

here are two examples of initializing a two-dimensional array

initializing 2d array in c# 

Access the two-dimensional array element in C#

Each element in the two-dimensional array has row-index and column-index that we can access the element by them.

The example shows you what will you do print elements in the array depending on the indices:-

access element of 2d array

Two-dimensional array length in C#

  • The length can be calculated using array.length
  • The total no of elements can be calculated by multiplying the size of all the dimensions.
int [,] arr; int arrlength= arr.Length; // x*y the total numbers of elements

or you can get with  multiplying all dimension

for (int i = 0; i < arr.Rank; i++) {
    total *= array3D.GetLength(i);
}

Looping array elements in C#

by using the for loop and the( width and height )of the 2d array we can looping the 2d array elements.

looping 2d array

Two-dimensional Arrays in Python

Python support multi-dimensional arrays.

  • It is an array of array.
  • It is accessed by using the two indices instead of one.

multi-dimensional array declaration in Python

  • A two-dimensional array is multiple lists within a list, where each list is a collection of values and each list is arranged in a separate row.
  • There are many structures you can use for storing a 2D array.
  • You can use function zeros() where all the elements of each array will be initialized to zero .
 from numpy import zeros
# Calling zeros() to create an int array of 2 rows and 2 columns
a = zeros([2,2], int)
print(a)  

the output is  [[0 0] [0 0]]

  • You can use function ones() where all the elements of each array will be initialized to one.
from numpy import ones
# Calling ones() to create an int array of 2 rows and 2 columns
a = ones([2,2], int)
print(a) 

the output is [[1 1]  [1 1]]

  • You can use a function array() function to initialize the 2d array.

from numpy import array
# Calling array() to create an int array of 2 rows and 3 columns
a = array([[5,4,3], [4,2,1]], int)
print(a)

the output is [[5 4 3] [4 2 1]]

 Access the multi-dimensional array element in Python

  • Each element in the two-dimensional array has row-index and column-index that we can access the element by them.

access element in python 2d array

multi-dimensional array length in Python

  • The length can be calculated using len()
  • you can get the height and the width of the array "list" by using len() function

multi-dimensional array length in python

Looping multi-dimensional elements in Python

by using the for loop

  •  the for-loop variable in Python can iterate not only over a range(), but generally over all the elements of any sequence.

looping multi array in python

the output will be  

1 2 3 4 

5 6 

7 8 9 

Multi-dimensional Arrays in java

  • Java support multi-dimensional arrays
  • IT is an array of array.
  • It is accessed by using the two indices.
  • Both row-index and column-index start at 0.
  • The two-dimensional is declared with [ ][ ] after the data type.
  • The multi-dimensional array is declared as [ ][ ][ ]....[n]

Two-dimensional array declaration in C#

datatype[][] arrayName;

Data Type  : It define the element type of the array.
[ ][ ] : It define the dimensions of the array
arrayName: It is the Name of array

  • the three-dimensional declared with [  ][  ][ ]
  • multi-dimensional array declared with [ ][ ][ ].....[Nth dimension].

here are two examples of two-dimensional and three-dimensional  array

 multi-dimensional array in java

Access the two-dimensional array element in Java

  • Each element in the two-dimensional array has row-index and column-index that we can access the element by them.

The example shows you what will you do to print elements in the array depending on the indices:-

access 2d array in java

Two-dimensional array length in java

  • The length can be calculated using array.length that will be the number of arrays inside it.

2d array length in java

Looping two-dimensional array elements in java

by using the for loop and the( rows and columns)of the two-dimensional array we can be looping the two-dimensional array elements.

looping 2d array in java

Looping three-dimensional array in java

3d array in java


See Also


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