# Multidimensional array in c++ with an example

Updated on June 13, 2016

## What is multi dimensional array?

We know about one-dimensional and two-dimensional arrays. But the dimensions are not limited to only two dimensions. When we access an array with more than two indexes then we call that array as a multi-dimensional array. The multi-dimensional array has more than one index. When an array is accessed using three indexes we call that as 3D Array and when it is accessed using four indexes we call as a 4D array and so on.

In this example, I am going to create a three-dimensional array and then put some values in it. Finally, I will read this three dimensional and display the result.

## Multidimensional array declaration

A three-dimensional array can be declared as shown below:

```//Sample 01: Declare an three dimentional Array
int ThreeDArray[3][3][2];

```

In the above example, we declared an array with 3 rows, 3 columns, and 2 slabs. Similarly, you can declare 4-Dimensional, 5-Dimensional arrays. The first square bracket represents rows, second square bracket represents columns and third one represents the slabs of rows and columns.

## Writing to Multidimensional array

Three “for” loops are used to populate the arrays. We populated first slab (Or first two-dimensional array) with the value of 1. The second slab is populated with the value of 2. Below is the code:

```//Sample 02: Initialize the array.
for(int row=0; row<3; row++)
{
for(int col=0; col<3; col++)
{
for(int depth = 0; depth<2; depth++)
{
if (depth == 0)
ThreeDArray[row][col][depth] = 1;
else
ThreeDArray[row][col][depth] = 2;
}
}
}```

Note the loop formation. The first loop represents iteration over Slabs and the second one represents iteration over rows and third one represents iteration over columns. Once, the array is populated, it will look like what is shown below:

The array is read the same way it was written. In our example, we read the array slab by slab. That is we read the three-dimensional array treating it like a two 2-Dimensional array. Below is code that reads the data from the array:

```//Sample 03: Read the array.
for(int depth = 0; depth<2; depth++)
{
for(int row=0; row<3; row++)
{
for(int col=0; col<3; col++)
{
printf("3DArray[%d][%d][%d] = %d\n",
row,col,depth,
ThreeDArray[row][col][depth] );
}
}
}```

## 5. Complete Code Example of Multidimensional array

The complete Example is listed below:

```/ TestIt.cpp : Defines the entry point for
//the console application.

//

#include "stdafx.h"
#include "conio.h"
int _tmain(int argc, _TCHAR* argv[])
{
//Sample 01: Declare an three dimentional Array
int ThreeDArray[3][3][2];

//Sample 02: Initialize the array.
for(int row=0; row<3; row++)
{
for(int col=0; col<3; col++)
{
for(int depth = 0; depth<2; depth++)
{
if (depth == 0)
ThreeDArray[row][col][depth] = 1;
else
ThreeDArray[row][col][depth] = 2;
}
}
}

for(int depth = 0; depth<2; depth++)
{
for(int row=0; row<3; row++)
{
for(int col=0; col<3; col++)
{
printf("3DArray[%d][%d][%d] = %d\n",
row,col,depth,
ThreeDArray[row][col][depth] );
}
}
}
getch();
return 0;
}```

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