Skip to main content

Q) What are the difference between static variables and instance variables?




A)
No
                      Static variables
No
                   Instance variables
1
Per class only one copy irrespective of number of  objects
1
Per object one separate copy
2
It is used to represent entire class information but not individual object information
2
Meant for representing individual object information
3
Doesn’t contribute to the size of object
3
Contribute to the size of the object
4
Shared by each object and manipulated by the behaviour of the object
4
Owned by one object
5
Comes into existence as soon as the class is loaded and before any object is created
5
Comes into existence only when object is created
6
memory is deallocated when class is unloaded
6
memory is deallodated only when the object is garbage collected
7
Both static and instance method can access them
7
Only instance methods can access them  and static methods can’t refer them
8
Can refer both of them with class name and object name
8
Can’t refer them with class

Comments

Post a Comment

Popular posts from this blog

Q) Explain repeated deletion of records.

A) //RepeatedDeletion.java import java.util.Scanner; import java.sql.*; class RepeatedDeletion {        public static void main(String[] args) {               Connection con= DriverManager. getConnection ( "jdbc:odbc:prince" , "scott" , "tiger" );               PreparedStatement ps=con.PreparedStatement( "DELETE FROM ACCOUNT WHERE ACCNO=?" );               Scanner s= new Scanner(System. in );               while ( true )               {                      System. out .println( "Enter accno : " );      ...
Post a Comment
Read more

Introduction

1) What is not JDBC? 2) What is the purpose of JDBC? 3) What is ODBC? 4) What is JDBC? 5) What is JDBC architecture? 6) What is JDBC client? What are its responsibilities? 7) What is JDBC API?  8) What is driver manager? 9) What is JDBC driver? What is its role in java database connection? 10) What is database server?
Post a Comment
Read more

Q) Explain about nested classes?

A) ->defining a class with in another class is known as nesting of the class. Ex: class A {        class B        {                      } //nested class, and inner class.because it is not static class. } //enclosing class or outer class. ->static class is declared in inside an another class then it does not become an inner class. Note: non-static nested class is known as “inner class”. In the above example class B is nested but not an inner class. Ex: class D {        static c        {                      } //nested class, but not an inner class , because of static class. } //outer class. ->we have three different kinds of inner classes. 1) Member inner class 2) Meth...
Post a Comment
Read more