Java Array Initialization

Java Array Initialization

Once we create an array every element by default initialize by default values.

example 1:

         int [ ] x =new int [ 3];

          System.out.println(x[0]);         o/p is    0            (default initial value)

          System.out.println(x[1]);          o/p is    0            (default initial value)

          System.out.println(x[2]);         o/p is    0            (default initial value)

          System.out.println(x);               o/p is      [ I@3e25a5

surprise What is this number???

Remember Carefully that whenever we are trying to print any reference variable internally toString()

the method will be called which is by default implemented to return in the following from.

                Classname@hashcode_in_hexadecimalform

                      means

                   [ is 1-D array

                   I is for Integer class

                   @3e25a5 hashcode (For every system it is different)

          List of corresponding classes:

example 2:
int [ ] [ ] x = new int [3] [ 2]
System.out.println(x);               o/p is      [ [  I@3e15a9
System.out.println(x[0]);               o/p is      [  I@5e25a5
System.out.println(x[0][0]);               o/p is       0      (default initial value)

let take a look at the memory representation:-

example 3:

int [ ] [ ] x= new int [ 3] [ ];

             System.out.println(x);                        o/p is      [ [  I@3e15a9

System.out.println(x[0]);                   o/p is    null
System.out.println(x[0][0]);               no o/p we will get "NullPointerException"
because we are trying to operate on null.

Once we creates an array every array element by default initialize values ,if we are not satisfied with default values then we can override these values with our customized values.
for example:
int [ ] x= new int [3];
x[0]=40;
x[1]=50;
x[2]=60;
System.out.println(x[0])    o/p is         40;
System.out.println(x[1])    o/p is         50;
System.out.println(x[2])    o/p is         60;