Two dimensional array is nothing but set of many one-dimensional array which is represented in usually rows and columns but they are stored in the continuous memory location. The syntax of the 2-D array is
int twoD[][] = new int[4][5];
It allocates 4×5 int elements in an array which internally stores 80 bytes of memory(If one int takes 4 bytes of memory).
We can also assign the elements to an array dynamically and the syntax goes like this :
int[][] a={{1,2,3},{4,5,6},{8,9,10}};
We can also allocate row with different columns and this type of an array is called as a jagged array.
int[][] a={{1,2,3},{5,6},{8,9,10,11}};
Sample code goes here:
import java.util.*;
class arraydemo
{
public static void main(String args[])
{
Scanner scan=new Scanner(System.in);
int r,c,a[][];
System.out.println("Enter the number of rows");
r=scan.nextInt(); //Number of rows in an array
System.out.println("Enter the number of columns");
c=scan.nextInt(); //number of columns in an array
a=new int[r][c]; //To initialize two dimensional array
System.out.println("Enter the elements in an array");
for(int i=0;i<r;i++)
{
for(int j=0;j<c;j++)
{
a[i][j]=scan.nextInt(); //To input the elements from an user
}
}
System.out.println("The elements in an array");
for(int i=0;i<r;i++)
{
for(int j=0;j<c;j++)
{
System.out.print(a[i][j]+" "); //Display the elements in a matrix form
}
System.out.println("");
}
}
}