#4 Known is a drop! Class Variables -Static Variable and Instance variable

A class can have two types of variable:
1.Static Variable
2.Instance Variable

STATIC VARIABLE:

• Sometimes, you want to have variables that are common to all objects. This is accomplished with the static modifier.

• Fields that have the static modifier in their declaration are called static fields or class variables.

• Every instance of the class shares a class variable, which is in one fixed location in memory.
  Static (class-level) variables can be manipulated directly using the class name, without instantiating the class.

• Static variables can be accessed with class name.

• Static variables can be used both in static methods and non static methods without using object reference.

• Value assigned to static variable can be changed anytime, at any part of the program.
  
  

Instance Variables:

• Instance Variables (Non-Static Fields) Technically speaking, objects store their individual states in "non-static fields", that is, fields declared without the static keyword.

• Non-static fields are also known as instance variables because their values are unique to each instance of a class (to each object, in other words);

• Non static variables/instance variables can be used in non static method directly(no need of object reference),whereas while using instance variables in static methods,object ref is needed.