I have to create all the method signatures in the ResizableArrayList and then fill it in with comments. And each method is supposed to be blank with a return null or --1. How do i do this?

For some reason I thought your question was

I have to create a method signature but don't know how to Type?

and was a joke... how silly of me

Method signatures, I assume your assignment is to "plan" what methods should be in a ResizableArrayList.

Open notepad or get a piece of paper and write down what you think you might want to be able to do with a ResizableArrayList?

one suggestion would be to resize it maybe you might want it to fly? no, well don't write that down, its not a useful method!

done that? Those are your public methods. Now write own all the methods that those methods might need to use, but the user will never want to use (if not used properly they might mess everything up) these will be your private methods!

Now write the class with those methods in, with a comment or description inside.

well done

If you cannot write a class with a method in, go look at some tutorials for writing a hello world application. OR take a look at your notes (which hopefully will be on-line, cos you didn't go to the lessons/lectures/weren't paying attention when you were supposed to be learning it)