Skip to main content

Q) What is a constructor?




A)
A specialized method of a class is known as constructor. A constructor is not the behavior of the object. Only instance methods of the class are only behavior. A constructor is different from an instance method in the fallowing areas.
1. Name
2. Return type
3. Type of calling
4. Time of calling
5. Frequency of calling
6. Purpose
A constructor is a specialized method of a class whose name and class name is same. And doesn’t have any return type. Not even void.
Ex:
class A
{
     A ()
        {
         }//constructor
}
Note :
If we give return type to the constructor, it will no more be acting as constructor. It becomes a normal method.
Ex:
class a
{
     Void a ()
        {
         }//instance method, not a constructor
}
Additional:
Normal method and class name may have same name. But the difference is the constructor. Does not contain return type, the normal method contain return type.

Comments

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 : " );      ...

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?

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...