First off, welcome to the world of coding! It is tough to tell exactly the problem without more insight. By going off what you wrote, this structure may be within a class, therefore it is unreachable within another file unless you have an instance of that class. There are a few options. The first being, make this structure global so it can be used everywhere. This is not good practice though. So the real solution is to design your code in a way that this structure is only accessible when needed. Hopefully you can post more details about what you are trying to do so my answer can be a little more meaningful!