What is the difference between an ARRAY
and a LIST?
Answer1
Array is collection of homogeneous elements.
List is collection of heterogeneous elements.
For Array memory allocated is static and continuous.
For List memory allocated is dynamic and Random.
Array: User need not have to keep in track of next memory allocation.
List: User has to keep in Track of next location where memory is
allocated.
Answer2
Array uses direct access of stored members, list uses sequencial access
for members.
//With Array you have direct access to memory position 5
Object x = a[5]; // x takes directly a reference to 5th element of array
//With the list you have to cross all previous nodes in order to get the
5th node:
list mylist;
list::iterator it;
for( it = list.begin() ; it != list.end() ; it++ )
{
if( i==5)
{
x = *it;
break;
}
i++;
}
Does c++ support multilevel and multiple inheritance?
Yes.
What is a template?
Templates allow to create generic functions that admit any data type as
parameters and return value without having to overload the function with
all the possible data types. Until certain point they fulfill the
functionality of a macro. Its prototype is any of the two following
ones:
template <class indetifier> function_declaration; template <typename
indetifier> function_declaration;
The only difference between both prototypes is the use of keyword class
or typename, its use is indistinct since both expressions have exactly
the same meaning and behave exactly the same way.
Define a constructor - What it is and how it might be called (2
methods).
Answer1
constructor is a member function of the class, with the name of the
function being the same as the class name. It also specifies how the
object should be initialized.
Ways of calling constructor:
1) Implicitly: automatically by complier when an object is created.
2) Calling the constructors explicitly is possible, but it makes the
code unverifiable.
Answer2
class Point2D{
int x; int y;
public Point2D() : x(0) , y(0) {} //default (no argument) constructor
};
main(){
Point2D MyPoint; // Implicit Constructor call. In order to allocate
memory on stack, the default constructor is implicitly called.
Point2D * pPoint = new Point2D(); // Explicit Constructor call. In order
to allocate memory on HEAP we call the default constructor.
You
have two pairs: new() and delete() and another pair : alloc() and
free().
Explain differences between eg. new() and malloc()
Answer1
1.) “new and delete” are preprocessors while “malloc() and free()” are
functions. [we dont use brackets will calling new or delete].
2.) no need of allocate the memory while using “new” but in “malloc()”
we have to use “sizeof()”.
3.) “new” will initlize the new memory to 0 but “malloc()” gives random
value in the new alloted memory location [better to use calloc()]
Answer2
new() allocates continous space for the object instace
malloc() allocates distributed space.
new() is castless, meaning that allocates memory for this specific type,
malloc(), calloc() allocate space for void * that is cated to the
specific class type pointer.
What is the difference between class and structure?
Structure: Initially (in C) a structure was used to bundle different
type of data types together to perform a particular functionality. But
C++ extended the structure to contain functions also. The major
difference is that all declarations inside a structure are by default
public.
Class: Class is a successor of Structure. By default all the members
inside the class are private.
Page Numbers
:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
