Double Dimension Array in Java

A 2-D array or double dimension array is a continuous location in memory where elements of the same type (datatype) are stored. A 2-D array consists of rows and columns where an element is stored at the cross-section of row and column known as a location. A location is accessed with the help of indeces of rows and columns as shown in the figure below.

2-d array in java

To use an array in a program, you must declare an array first, then assign values to it, and then access it within a loop.

Array Declaration

To declare an integer array:
```
 int a[][] = new int[4][4];
```
To declare a String array:
```
 String a[][] = new String[5][45];
```

To assign values to an array:

System.out.println("Enter "+(4*4)+" integer values");

 try{

    for(i = 0; i < 4; i++){
      for(j = 0; j < 4; j++){
         a[i][j] = Integer.parseInt(br.readLine());
       }
    }

}catch(Exception e){}

Accessing array elements

 for(i = 0; i < 4; i++){
  for(j = 0; j < 4; j++){
     System.out.println(a[i][j]);
   }
 }

Array Initialization

Integer array:

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

String array:

 String str[][] = { 
                 {"Java", "is", "Robust and Secure."},
                 {"Java", "is", "platform-independent."},
                 {"Java", "is", "an", "Object-Oriented."}
               };

Double Dimension Array in Java

Array Declaration

Array Initialization

Related Notes