Java Static Constructor : is it possible to create static constructor?

1.Is it possible to create static constructor in java?

• No. We can not create constructor with static.
• If we try to create a static constructor compile time error will come: Illegal modifier for the constructor

2.What is the real use of constructor in java? 

• Constructors will be used to assign instance variables with default values.
• Whenever object is created constructor will be called so the default values for the instance variables will be assigned in this constructor.
• Top 15 Java Interview Questions on Constructors

1. public class ConstructorDemo {
2.  
3.  int a,b;
4. 
   
5. ConstructorDemo (int x, int y){
6.  
7. a=x;
8. b=y;
9.  
10. }
11. public static void main(String[] args) {
12.  
13.         ConstructorDemo ob= new ConstructorDemo ();
14.  
15.     }
16. }

3. What is the use of static in java?

• Static keyword is mainly used for memory management.
• Static variables get memory when class loading itself.
• Static variables can be used to point common property all objects.

4.Is there any alternative solution for static constructor in java

• Static means class level.
• Constructor will be use to assign initial values for instance variables
• static and constructor are different and opposite from each other.
• To assign initial values for instance variable we use constructor.
• To assign static variables we use Static Blocks
• We can use static blocks to initialize static variables in java.

5.what is static block in java?

• Class loading time itself these variables gets memory
• Static methods are the methods with static keyword are class level. without creating the object of the class we can call these static methods.


1. public static void show(){ 
2.  
3. }


• Static block also known as static initializer
• Static blocks are the blocks with static keyword.
• Static blocks wont have any name in its prototype.
• Static blocks are class level.
• Static block will be executed only once.
• No return statements.
• No arguments.
• No this or super keywords supported.
 

1. static{ 
2.  
3.  }

6. write a java program to assign static variables using static block

1. package com.staticInitializer;
2.  
3. class StaticBlockDemo 
4. {
5.  
6. static{
7.       System.out.println("First static block executed");
8. }
9.  
10. static{
11.      System.out.println("Second static block executed");
12. }
13.  
14. static{
15.      System.out.println("Third static block executed");
16. }
17.  
18. }
     

Output:

1. First static block executed
2. Second static block executed
3. Third static block executed

  1.Static Variables 

  2.Static Methods 

  3.Static Blocks

  4.Main method