What are proxy objects?

View previous topic View next topic Go down

What are proxy objects?

Post  Admin on Sun Jan 31, 2010 5:36 pm

Answer:
Objects that stand for other objects are called proxy objects or surrogates.
Example:
template<class T>
class Array2D
{
public:
class Array1D
{
public:
T& operator[] (int index);
const T& operator[] (int index) const;
...
};
Array1D operator[] (int index);
const Array1D operator[] (int index) const;
};
The following then becomes legal:
Array2D<float>data(10,20);
........
cout<<data[3][6]; // fine
Here data[3] yields an Array1D object and the operator [] invocation on that object yields the float in position(3,6) of the original two dimensional array. Clients of the Array2D class need not be aware of the presence of the Array1D class. Objects of this latter class stand for one-dimensional array objects that, conceptually, do not exist for clients of Array2D. Such clients program as if they were using real, live, two-dimensional arrays. Each Array1D object stands for a one-dimensional array that is absent from a conceptual model used by the clients of Array2D. In the above example, Array1D is a proxy class. Its instances stand for one-dimensional arrays that, conceptually, do not exist.

Database interview questions

Click here More information available

Admin
Admin

Posts : 71
Join date : 2010-01-21

View user profile http://campus-interview.co.cc

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum