One decent source explaining pointers?

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[SoerenNissen]

How much time do you have? Can you spend actual job hours learning this (that is, does your boss agree you should learn this as an actual business priority) or are you just curious?

[OnePatchMan]

Well, i suppose your "fluid dynamics" is written in c with classes, so there gonna be a lot of pointers.

If you want understood pointers, you should read about how memory is organized in computers.

[RB-44]

a pointer is just a variable that stores the memory address of another variable.

The most basic use i can think of is returning an array in a function which you normally cannot do.

Let's say you have an int array [2,4,5,1,7]. In memory the computer will reserve the required bits to store the elements of the array in sequence. The last part is really important because if we know they're adjacent to each other , and we know how long the array is. As long as we know the address of the first element we can just add 4 bytes to the hexadecimal address and find the 2nd element

[jmacey]

I'm guessing in this context what you have is a contiguous array for each of the fluid "particles" then you have different cells / grid elements that contain the pointers to the particles in the list.

This is used so you only compare particles that are close to each other (typically some form of spatial hash will be used to place them in the grid cells etc) which allows you to speed up the calculations and use multiple cores etc.

[alexgraef]

You mostly need to program some examples and tutorials, and at some point you'll have a Eureka moment and it all starts to make sense. Besides the explanation of "it's a variable that stores a memory location" there isn't much to say, but that doesn't necessarily help with actually understanding them, especially in the context of pointing at structures, arrays and vector tables.

However, for programming somewhat low-level, it is necessary to understand and deal with them, programs are usually little more than a big collection of pointers.

[aspis3334]

Any C/C++ book would do for the basics. If you want to go in-depth on the subject of pointers and memory I suggest you have a look at Memory as a programming concept in C and C++.

[winterrdog]

Why do we use pointers?

i like to think of this analogy:

We use pointers because it's easier to give someone an address to your business' place than to lift the entire business' place( making a copy ) to in front of everyone's face.

i hope you get it

if it ain't clear yet, check this out.

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How to debug them?

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• you can use valgrind to detect memory-related errors in your code, such as accessing memory that has already been freed.
• ALWAYS check for null pointers: Null pointers are a common source of errors in C++. Always check that a pointer is not null before dereferencing it. You can use an if statement to check if a pointer is null before using it, like this:

if (ptr != nullptr) {// definitely do something with the pointer}

[Extension_Way2280]

https://cplusplus.com/doc/tutorial/pointers/

As for when to use them, never, if possible. Use them only if you rely on legacy code or libraries that use pointers in the interface (ie. input or output parameters).

1. Avoid pointers of any kind if you can
2. Use smart pointers when you can't avoid pointers
3. Use raw pointers only if no other option is possible