Java Multi Dimensions Array - Java Tutorials

Multidimensional Arrays in Java

In java, the grouping of same type of elements for storing under the same name is done using array.An array can hold any type of data and can have multidimensional. For accessing elements of array we use its index.

In other words, we can say that array is the set of same type of data stored under the same roof.

Given below the example to provide you an idea-how array works?

Declaring one dimension array 

type var-name[ ];

For example :

If an array is declared as : int Dev[3], it means it has 4 element from Dev[0] to Dev[3].

Allocating memory to arrays :

var-name = new type[size];  

Example :

Dev = new int[12];

Assigning and accessing value from array

You can assign value directly, like this :

Dev[0] = 12; // this will assign value to first element.
Dev[1] = 30  // this will assign value to second element.

Array can also be assigned when they are declared as :

int Dev[] = {3, 12, 21, 30, 39, 48};

You can access array element like this :

System.out.println(Dev[3]);   // This will print 4th element of array.

Example :

public class DevArray {
public static void main(String[] args) {
double[] devList = {1.9, 2.9, 3.4, 3.5};

// Print all the array elements
for (double element: devList) {
System.out.println(element);
}
}
}

Output :

Multidimensional array :

In java, multidimensional arrays are actually arrays of arrays. For example, you can declare a two dimensional array as :

int twoD[][]=new int [4][5];

You can also declare a three dimensional array as :

int threeD[][][]= new int [3][4][5];

Example :

Class TwoDmatrix{
  public static void main(String args[]) {
    int twoDm[][]= new int[4][5];
    int i,j,k=0;

    for(i=0;i<4;i++)
      for(j=0;j<5;j++) {
         twoDm[i][j]=k;
         k++;
      }
    for(i=0;i<4;i++)
      for(j=0;j<5;j++) {
         System.out.println(twoDm[i][j]+"")
         System.out.println();
      }
   }
 }
 

Output :