Winter Bootcamp in ML and IoT in Jaipur
 Course content (For Bootcamp & Winter Training):- Machine Learning (ML) || Internet of Things (IoT) || Register for winter bootcamp
0 like 0 dislike
in Tutorial & Interview questions by (3.4k points)

Multi-dimensional arrays

1 Answer

0 like 0 dislike
by (3.4k points)
Best answer

The C programming language allows multidimensional arrays. Here is the general form of a multidimensional array declaration −

type name[size1][size2]...[sizeN];

For example, the following declaration creates a three dimensional (5 x 10 x 4) integer array:

int arr[5][10][4];

Two-dimensional Arrays

The simplest form of multidimensional array is the two-dimensional array. A two-dimensional array is, in essence, a list of one-dimensional arrays. To declare a two-dimensional integer array of dimensions m x n, we can write as follows:

type arrayName[m][n];

Where type can be any valid C data type (int, float, etc.) and arrayName can be any valid C identifier. A twodimensional array can be visualized as a table with m rows and n columns. Note: The order does matter in C. The array int a[4][3] is not the same as the array int a[3][4]. The number of rows comes first as C is a row-major language.

A two-dimensional array a, which contains three rows and four columns can be shown as follows:


Thus, every element in the array a is identified by an element name of the form a[i][j], where a is the name of the array, i represents which row, and j represents which column. Recall that rows and columns are zero indexed. This is very similar to mathematical notation for subscripting 2-D matrices.

Initializing Two-Dimensional Arrays

Multidimensional arrays may be initialized by specifying bracketed values for each row. The following define an array with 3 rows where each row has 4 columns.

int a[3][4] = {     

{0, 1, 2, 3} ,   /*  initializers for row indexed by 0 */   

{4, 5, 6, 7} ,   /*  initializers for row indexed by 1 */   

{8, 9, 10, 11}   /*  initializers for row indexed by 2 */ };

The nested braces, which indicate the intended row, are optional. The following initialization is equivalent to the previous example:

int a[3][4] = {0,1,2,3,4,5,6,7,8,9,10,11};

While the method of creating arrays with nested braces is optional, it is strongly encouraged as it is more readable and clearer.

Accessing Two-Dimensional Array Elements

An element in a two-dimensional array is accessed by using the subscripts, i.e., row index and column index of the array. For example −

int val = a[2][3];

The above statement will take the 4th element from the 3rd row of the array. Let us check the following program where we have used a nested loop to handle a two-dimensional array:

#include <stdio.h> 

int main () 


   /* an array with 5 rows and 2 columns*/   int a[5][2] = { {0,0}, {1,2}, {2,4}, {3,6},{4,8}};

int i, j; 

   /* output each array element's value */   

for ( i = 0; i < 5; i++ ) 


for ( j = 0; j < 2; j++ ) 


printf("a[%d][%d] = %d\n", i,j, a[i][j] );      



return 0; 


When the above code is compiled and executed, it produces the following result:

a[0][0]: 0 

a[0][1]: 0 

a[1][0]: 1 

a[1][1]: 2 

a[2][0]: 2 

a[2][1]: 4 

a[3][0]: 3 

a[3][1]: 6 

a[4][0]: 4 

a[4][1]: 8

Three-Dimensional array:


A 3D array is essentially an array of arrays of arrays: it's an array or collection of 2D arrays, and a 2D array is an array of 1D arrays.

3D array memory map:


Initializing a 3D Array:

double cprogram[3][2][4]={ 

{{-0.1, 0.22, 0.3, 4.3}, {2.3, 4.7, -0.9, 2}}, 

{{0.9, 3.6, 4.5, 4}, {1.2, 2.4, 0.22, -1}}, 

{{8.2, 3.12, 34.2, 0.1}, {2.1, 3.2, 4.3, -2.0}} 


We can have arrays with any number of dimensions, although it is likely that most of the arrays that are created will be of one or two dimensions.

Winter 10 Days boot-camp classes(7 HRS Daily) will start from 5, 20 & 27 December 2019 in:
1) Internet of things(IoT) Using RASPBERRY-PI
2) Machine Learning (ML)

70% OFF| Fee-INR 3,000/-

Limited seats!! Hurry up!!

[[ CALL - 07976731765 ]]

Some Study Resources are compiled from original Stack Overflow Documentation, the content is developed by the different experts at Stack Overflow. Study resources are released under Creative Commons BY-SA. Images may be copyright of their respective owners. This website is for self-learning and not affiliated with Stack Overflow. All trademarks and registered trademarks are the property of their respective company owners. Please send feedback and corrections to

Goeduhub Important Lists Our Youtube Channels (For free E-learning)
About Us List of IITs Goeduhub Technologies
Contact Us List of NITs AI and Big Data-HADOOP E-Learning Series
  List of PSUs Smart Learning PLC-SCADA, IoT and Raspberry-PI
  List of Exams After Graduation