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Q) what are Different kinds of variables ?

Class  A
{
  //user defined data type created.
}

Class A
{
  Static int a;         //primitive , class variable
Static student s;    //user defined , class variable
Int b;                   //primitive , instance variable
Student s2;         // user defined , instance variable
Void a()
  {
      Int a;            //primitive , local variable
    Student s1;    //user defined , local variable
  }
}

Note:
  In java user defined variables are not objects they are “references”.
For class scoped references variables, JVM gives “null” value by default.
“Null “indicates that the reference is pointing to no object.

other notes :
Instance variables residential place is heap area of RAM and local variable residential place is stack in RAM.

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