Skip to main content

Q) How are class scoped variables classified?



A)

1) Instance variables (per instance variables)
2) Class variables (per class variables)
Per instance means for every object that no. of variables created.
Per class means only one variable is created.
Class scoped variables are 2 types
Static and non-static variables static variables are called class variables.

Ex:
Class test
{
     int a;    //instance variable
Static int b; //class variable
Void A ()
   {
       a=100;
     b=200;
   int c;  //local variable
  }
Void B()
     {
       a=90;
     b=80;
     c=50; //error
     }
}

->In the above example  “a”  is non-static but has class scope. i.e., it is available all the methods of the class.
->non-static variable of a class is known as Instance variable.
->In the above example “b’ is static.
->static variable of a class is known as “class variable” in java.
->local variables cannot be static.

Comments

Post a Comment

Popular posts from this blog

Q) What is JDBC driver? What is its role in java database connection?

A) ->A translation software written in java according o JDBC specification is nothing but “JDBC driver”. -> JDBC driver implements JDBC API. Use single API. JDBC driver role: They are 4 roles   1)       Establishing connection between JDBC client and database server. 2)       Receiving JDBC method calls made by JDBC client while performing database (CRUD) operations. 3)       Translating java method calls into DBMS understandable calls and forwarding them to database server. 4)       Receiving the results from database server. Translating them into java format and handling over the same to the JDBC client.
Post a Comment
Read more

Q) What is ODBC?

A) ->open database connectivity is a technology from MS that enables any language program (other than java) to communication with database Management System. ->in java program ODBC is directly not allowed for the fallowing reasons 1) OS dependency 2) Procedural oriented approach 3) Security thread
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