C++ Questions

The main aim of the namespace is to understand the logical units of the program and to make the program so robust.

Default constructors has no arguments

- Friend classes are useful when a class wants to hide features from users which are needed only by another, tightly coupled class. 

- Implementation details can be kept safe by providing friend status to a tightly cohesive class.

i.) Const - This variable means that if the memory is initialised once, it should not be altered by a program. 

ii.) Volatile - This variable means that the value in the memory location can be altered even though nothing in the program code modifies the contents. 

iii.) Mutable - This variable means that a particular member of a structure or class can be altered even if a particular structure variable, class, or class member function is constant.

Referencee is stored in stack

In C++, void represents the absence of type, so void pointers are pointers that point to a value that has no type. The void pointers can point to any data type.

You can declare void pointer as follows:

void *p;

Wrapper classes wrap primitive values in a class and offers utility to access them through objects. Some of the primitive wrapper data types are:

Byte, short, int, long, float, double, char, Boolean.

Example: 

Create a class name VectorAdd to populate it with integer values using the add(int, object) method.

public class VectorAdd

{

       public static void main(String argv[])

       {

             Vector v = new Vector();

             v.add(0,new Integer(10));

             v.add(1,new Integer(20));

             v.add(2,new Integer(30));

             for(int i=0; i < v.size();i ++)

             {

                  Integer iw =(Integer) v.get(i);

                  System.out.println(iw);

             }

       }

}