Tuesday, October 14, 2008

Necessity for Object Oriented Programming Language.

What is the necessity for Object Oriented Programming Language?

In simple terms,  why we have moved from C(Procedural Language) to C++(Object Oriented Language)  ?

In C we use user defined data types like Structure, Union etc, where as in C++ we use classes, here I will try to answer the above question in terms of using these different language elements:

1. The variables we use in a structure or union can be accessed any where in the program, this means,  that there is no proper security for data in C i.e. Procedural Langauage. Where as in c++ we have access specifiers like public, private, protected etc, which allows us to restrict the access to a particular variable. So unlike C, C++ has some control over the access to the data.

2. The variables/ elements of one structure are cannot be accessed in an other structure unless they are nested, so there is some access limitations for data in C. Where as in C++ the variables declared and used in one class are allowed/ restricted to get accessed by other classes throught the same access specifiers public, private, protected etc.

3. Function concepts is not supported by structures in C i.e, we cant declare a function as a structure member, where classes can have functions as their members. 

These are a few reasons, where there is a necessity to move from a structure oriented language to a object oriented language.

Saturday, September 20, 2008

Basic Queries of SQL ...

create a table:

CREATE TABLE table_name (column1 coulmn_type( ),column2 coulmn_type( ),column3 coulmn_type( ));

insert values into table:

INSERT INTO table_name (column1,column2,column3) VALUES (value1,value2,value3);

note: VARCHAR values must be used with single quotes, like, 'haree','apple' etc.

note: if you are inserting values to all the columns then you can use:

INSERT INTO table_name (value1,value2,value3);

retreive all columns of a table:

SELECT * FROM table_name;

retreive selected columns from a table:

SELECT column1,column2,column3 FROM table_name;

to view the structure of a table:

DESCRIBE table_name; (or) DESC table_name;

Oracle 10g, Html, Xml, Javascript, .Net

Recently I have started learning Oracle 10g, html, xml, javascript and also interested in learning .net technology so regularly from now I keep posting different concepts of what I learn, also I want to post about how to improve our blog and if there are any corrrections or suggestions or misconcepts please bring it to my notice at hari@gudigundla.com ...

Saturday, September 13, 2008

my experience...

Hello, my name is Hari Gudigundla, I completed my engineering in computer science and interested in blogging and now I have decided to blog what all I learn and experience in all aspects of computers I am interested in like learning new technologies, programming, web development etc. I will try to list out all interesting and important aspects which I consider may be useful for others. Hope I will continue this discussion...