Source: Google.Com
INFOSYS
1.Difference between C and C++?
a) C follows the procedural
programming paradigm while C++ is a multi-paradigm language (procedural as well
as object oriented)
In case of C, importance is given to the steps or procedure of the program
while C++ focuses on the data rather than the process.
Also, it is easier to implement/edit the code in case of C++ for the same
reason.
b) In case of C, the data is not secured while the data is secured (hidden) in
C++
This difference is due to specific OOP features like Data Hiding which are not
present in C.
c) C is a low-level language while C++ is a middle-level language
C is regarded as a low-level language (difficult interpretation & less user
friendly) while C++ has features of both low-level (concentration on what's
going on in the machine hardware) & high-level languages (concentration on
the program itself) & hence is regarded as a middle-level language.
d) C uses the top-down approach while C++ uses the bottom-up approach
In case of C, the program is formulated step by step, each step is processed into
detail while in C++, the base elements are first formulated which then are
linked together to give rise to larger systems.
e) C is function-driven while C++ is object-driven
Functions are the building blocks of a C program while objects are building
blocks of a C++ program.
f) C++ supports function overloading while C does not
Overloading means two functions having the same name in the same program. This
can be done only in C++ with the help of Polymorphism (an OOP feature)
g) We can use functions inside structures in C++ but not in C.
In case of C++, functions can be used inside a structure while structures
cannot contain functions in C.
h) The NAMESPACE feature in C++ is absent in case of C
C++ uses NAMESPACE which avoid name collisions. For instance, two students
enrolled in the same university cannot have the same roll number while two
students in different universities might have the same roll number. The
universities are two different namespace & hence contain the same roll
number (identifier) but the same university (one namespace) cannot have two
students with the same roll number (identifier)
i) The standard input & output functions differ in the two languages
C uses scanf & printf while C++ uses cin>> & cout<< as
their respective input & output functions
j) C++ allows the use of reference variables while C does not
Reference variables allow two variable names to point to the same memory
location. We cannot use these variables in C programming.
k) C++ supports Exception Handling while C does not.
C does not support it "formally" but it can always be implemented by
other methods. Though you don't have the framework to throw & catch
exceptions as in C++.
2.What is null pointer?
When referring to computer memory, a null pointer is
a command used to direct a software program or operating system to an empty
location in the computer memory. Commonly, the null pointer is used to denote
the end of a memory search or processing event. In computer programming, a null
pointer is a pointer that does not point to any object or function.
A nil pointer is a false value. For example, 1 > 2 is a nil statement.
In the programming language C, NULL is an available command that can be used,
where nil is an available command used in the Pascal programming language.
3.What are the 4 basics of OOP?
Abstraction, Inheritance, Encapsulation, and Polymorphism.
4.What you mean by Object Relational DBMS?
An object-relational database (ORD), or
object-relational database management system (ORDBMS), is a database management
system (DBMS) similar to a relational database, but with an object-oriented
database model: objects, classes and inheritance are directly supported in
database schemas and in the query language. In addition, just as with proper
relational systems, it supports extension of the data model with custom
data-types and methods.
5.Structural difference between bitmap and b-tree
index ?
Btree
It is made of branch nodes and leaf nodes. Branch nodes holds prefix key value
along with the link to the leaf node. The leaf node in turn contains the
indexed value and rowed.
Bitmap
It simply consists of bits for every single distinct value. It uses a string of
bits to quickly locate rows in a table. Used to index low cardinality
columns.
(The Happy Beginnings......)
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