Non static blocks in java example

Non Static Blocks in java

• When ever object created non static blocks will be executed before the execution of constructor
• Non static blocks are class level block which does not have prototype

1. package nonstaticblocks;
2. public class A {
3.  
4.    {
5.         
6.        System.out.println("non static block executed");
7.  
8.     }
9.  
10. }

What is the need of Non static blocks in java?

• To execute any logic whenever object is created irrespective of constructor used in object creation.

Who will execute Non static blocks?

• Non static blocks are automatically called by JVM for every object creation in java stack area

How many Non static blocks we can create?

• We can create any number of Non static blocks

Order of execution of non static blocks

• Order of execution of non static blocks will be order as they are defined.

1. package nonstaticblocks;
2. public class A {
3.  
4. {
5. 
   
6.   System.out.println("first block");
7. } 
8.  
9. {
10.  System.out.println("second block");
11. }
12.  
13. {
14.  System.out.println("third block");
15. }
16. public static void main(String[] args) {
17.   A obj= new A();
18. }
19. }

 Output:

1. first block
2. second block
3. third block

 Order of execution of non static blocks with respect to constructor?