Pointers and references?!? Help!

Hi,

I've been studying C++ for a few months now.. However, I just couldn't grasp completely how to apply pointers and references in codes. I think I understand how they work, though. I am having trouble with using it in my own functions. I am getting desperate! I tried to move on to more advanced subjects like classes and operator overloading, hoping that the idea of pointers and references will eventually sink in. But I guess, I needed to fully grasp those topics first since the knowledge of it is essential to other subjects.

Any suggestions on how I can understand it better?

Much appreciated..

What don't you understand about them?

Use references whenever possible, rather than pointers.
References cannot point to anything else after you initialize them, so if you always want it to refer to the same object and the object wasn't dynamically allocated, references are definitely the way to go.

Pointers have useful applications when allocating things on the heap, changing data located elsewhere, and also building your own data structures. References can also change data located elsewhere, because when you make a reference you are giving some datum an alias.

For example, you might see a function that accepts a reference to avoid making unnecessary copies of an object.

size_t length ( const string & val );

And you might see the same function implemented with pointers to support c-strings.

size_t length ( const char * val );

Both of these functions use data located elsewhere in the code and being able to refer to that data indirectly is part of pointers and references usefulness.

Can you write a function to swap the value of two variables? You can do this using either pointers and references.

Passing by const reference is often used with classes to avoid making an unnecessary and potentially expensive copy of the object (e.g most of the time std::string would be passed by const reference).