Variables and keywords

Variables:

Static Variable
Static variables belong to a class and not to any individual instance. The concept of serialization is concerned with the object’s current state. Only data associated with a specific instance of a class is serialized, therefore static member fields  are ignored during serialization.

Transient Variable
While serialization if you don’t want to save state of a variable. You have to mark that variable as Transient. Environment will know that this variable should be ignored and will not save the value of same.


Final :

Final is used to apply restrictions on class, method and variable. Final class can't be inherited, final method can't be overridden and final variable value can't be changed.

class FinalExample{
public static void main(String[] args){
final int x=100;
x=200;//Compile Time Error
}}

Finally :

Finally is used to place important code, it will be executed whether exception is handled or not.

class FinallyExample{
public static void main(String[] args){
try{
int x=300;
}catch(Exception e){System.out.println(e);}
finally{System.out.println("finally block is executed");}
}}


Finalize :

Finalize is used to perform clean up processing just before object is garbage collected.

class FinalizeExample{
public void finalize(){System.out.println("finalize called");}
public static void main(String[] args){
FinalizeExample f1=new FinalizeExample();
FinalizeExample f2=new FinalizeExample();
f1=null;
f2=null;
System.gc();
}}