Why use pointers?

Some things are too big to store on the stack and you need them in the heap. Those two words may be gibberish right now but it gives you a new thing to learn.

My advice is to learn pure C and make a few small programs with it. You'll see very soon why pointers are necessary.

It doesn’t “forward to”, it is a way to say “ehi, this data X is located at …”

Imagine having a big large data structure that takes up a lot of space. You have to pass it a function to perform some operations, but if pointers didn’t exist you would have to clone those data - which is expensive memory wise and probably time wise to. So instead of wasting either space or time, you simply pass a memory address to that data and using it you can access the original data.

Obviously if you have primitive data structures, such as integers, or that you know that aren’t expensive to clone, you can simply pass by value and call it a day (somewhere on learncpp theee is a very nice explanation of all of this)

A really simple way you can look at pointers is like this: every time you want to see my house, I could rebuild a complete copy of my house for you, but wouldn’t it be easier if I could give you a note with my house’s address so you could just visit it there?

In the second example, the note is an analogy for a pointer.

Something else that people haven't touched on yet is dynamic memory allocation. Whenever you create a new object you'll need a reference to it. That reference is a pointer.

I haven't used pointers for a long time, I only use smart pointers nowadays. As for your question: just changing the variable/replacing what’s already at the memory address, the answer is also "sometimes you can't" because some objects cannot be cloned or duplicated like sockets or threads.

There are things you'll want to do that will eventually require pointers. For example, as soon as you want a type that contains a reference that could be rebound, you need a pointer.

If you want to implement polymorphism you'll need pointers. If you instead want type erasure, you'll need pointers to implement your type erasure container.

Sure it's possible to implement a lot without pointers, but the code will be harder to write and will probably be slower.

Ton of thanks for all the replies and examples. Some of it is over my head at the moment but most of it has shed some light none of the self-teach material has gotten into, I appreciate that.

Letting this all sink then hitting the books again!

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Pointers also allow you to do fun and dangerous things like casting between types!

For example, if you're implementing your own memory allocator, at the base level your allocator only really cares about how many bytes are being requested (along with alignment, offset, other things) so you'd probably just implement it to return a char*, u8*, or void* pointing to the blob of memory you allocated with new, malloc, or whatever scheme you've cooked up. The calling code or higher level allocator code could then cast it to the actual type

IMHO pointers (raw or smart) are barely necessary in modern C++. In many cases, references and standard library classes like std::vector do whatever pointers do, but without the manual memory management. I use pointers for interacting with C libraries and in HIP/CUDA. In "pure" C++ the only thing that comes to mind is storing objects of different derived classes in a vector.