16. Explain what are Access specifiers in C++ class? What are the types?
Ans:
Access specifiers determine the
access rights for the statements or functions that follow it until the end of
class or another specifier is included. Access specifiers decide how the
members of the class can be accessed. There are three types of specifiers
• Private
• Public
• Protected
17. Explain what are Operators and explain with an example?
Ans:
Operators are specific operands
in C++ that is used to perform specific operations to obtain a result. The
different types of operators available for C++ are Assignment Operator,
Compound Assignment Operator, Arithmetic Operator, Increment Operator and so
on.
For example arithmetic operators,
you want to add two values a+b
#include
Using namespace std;
main ()
{
int a= 21 ;
int b= 10 ;
int c;
c= a + b;
cout << “Line 1- Value of c
is : ” << c << endl ;
return 0;
}
18. Explain what is a reference variable in C++?
Ans:
A reference variable is just like
a pointer with few differences. It is declared using & Operator. In other
words, reference is another name for an already existing variable.
19. Explain what is Polymorphism in C++?
Ans:
Polymorphism in C++ is the
ability to call different functions by using only one type of the function
call. Polymorphism is referred to codes, operations or objects that behave
differently in a different context.
For example, the addition
function can be used in many contests like
• 5+5 : Integer addition
• Medical+Internship : The same (
+ ) operator can be used with different meaning with strings
• 3.14 + 2.27 : The same ( + )
operator can be used for floating point addition
20. Explain what is C++ exceptional handling?
Ans:
The problem that arises during
execution of a program is referred as exceptional handling. The exceptional
handling in C++ is done by three keywords.
• Try: It identifies a block of
code for which particular exceptions will be activated
• Catch: The catch keyword
indicates the catching of an exception by an exception handler at the place in
a program
• Throw: When a problem exists
while running the code, the program throws an exception
21. Mention what are the types of Member Functions?
Ans:
The types of member functions are
• Simple functions
• Static functions
• Const functions
• Inline functions
• Friend functions
22. Explain what is multi-threading in C++?
Ans:
To run two or more programs
simultaneously multi-threading is useful. There are two types of
• Process-based: It handles the
concurrent execution of the program
• Thread-based: It deals with the
concurrent execution of pieces of the same program
23. Explain what is upcasting in C++?
Ans:
Upcasting is the act of
converting a sub class references or pointer into its super class reference or
pointer is called upcasting.
24. Explain what is pre-processor in C++?
Ans:
Pre-processors are the
directives, which give instruction to the compiler to pre-process the
information before actual compilation starts.
25. What is difference between C and C++ ?
Ans:
C++ is Multi-Paradigm ( not pure
OOP, supports both procedural and object oriented) while C follows procedural
style programming.
In C data security is less, but
in C++ you can use modifiers for your class members to make it inaccessible
from outside.
C follows top-down approach (
solution is created in step by step manner, like each step is processed into
details as we proceed ) but C++ follows a bottom-up approach ( where base
elements are established first and are linked to make complex solutions ).
C++ supports function overloading
while C does not support it.
C++ allows use of functions in
structures, but C does not permit that.
C++ supports reference variables
( two variables can point to same memory location ). C does not support this.
C does not have a built in
exception handling framework, though we can emulate it with other mechanism.
C++ directly supports exception handling, which makes life of developer easy.
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