Answers for "what is final keyword"

what it means when create final variable in java

First of all, final is a non-access modifier applicable only to 
a variable, a method or a class

When a variable is declared with final keyword, its value can’t be modified, 
essentially, a constant. This also means that you must initialize a 
final variable. If the final variable is a reference, this means that 
the variable cannot be re-bound to reference another object, but internal 
state of the object pointed by that reference variable can be changed 
i.e. you can add or remove elements from final array or final collection. 
  It is good practice to represent final variables in all uppercase, using 
  underscore to separate words.

java final meaning

private final String hello = "Hello World!";
/*
The keyword final states that the variable, method or class
associated will not have it's value changed.
*/

Final Keyword

The final keyword in java is used to restrict the user. The java final keyword can be used in many context. Final can be:

variable
method
class
The final keyword can be applied with the variables, a final variable that have no value it is called blank final variable or uninitialized final variable. It can be initialized in the constructor only. The blank final variable can be static also which will be initialized in the static block only.


Example
Final Variable : 
class Bike9{  
 final int speedlimit=90;//final variable  
 void run(){  
  speedlimit=400;  // Compile Time Error (Cant change final variable value)
 }  
 public static void main(String args[]){  
 Bike9 obj=new  Bike9();  
 obj.run();  
 }  
}//end of class 
Final Method : 
class Bike{  
  final void run(){System.out.println("running");}  
}  
     
class Honda extends Bike{  
   void run(){System.out.println("running safely with 100kmph");}  // Compile Time Error (Cant override final method)
     
   public static void main(String args[]){  
   Honda honda= new Honda();  
   honda.run();  
   }  
} 
Final Class : 
final class Bike{}  
  
class Honda1 extends Bike{  // Compile Time Error (Cant extend final class)
  void run(){System.out.println("running safely with 100kmph");}  
    
  public static void main(String args[]){  
  Honda1 honda= new Honda1();  
  honda.run();  
  }  
}