Common Uses For Pointers?

Question

I'm a programming student with two classes in C#, but I'm just taking my first class in C++, and thus I'm being exposed to pointers.

I know how they work, and the proper way to use them, but I wondered about some of the ways that professional programmers use pointers in their programs.

So how do you use pointers? Or do you?

This will help me understand some practical applications for pointers, so thanks!

Answer 1

Any time you'd use a reference in C#. A "reference" is just a pointer with fancy safety airbags around it.

I use pointers about once every six lines in the C++ code that I write. Off the top of my head, these are the most common uses:

• When I need to dynamically create an object whose lifetime exceeds the scope in which it was created.
• When I need to allocate an object whose size is unknown at compile time.
• When I need to transfer ownership of an object from one thing to another without actually copying it (like in a linked list/heap/whatever of really big, expensive structs)
• When I need to refer to the same object from two different places.
• When I need to slice an array without copying it.
• When I need to write directly to a specific region of memory (because it has memory-mapped IO).

Answer 2

For staters, you use them in your data structures, like linked list, etc. Anyplace you need dynamically allocated memory, that is, memory that you don't know the size of at compile-time, you will be using a pointer.