I am new to Groovy and, despite reading many articles and questions about this, I am still not clear of what is going on. From what I understood so far, when you create a new array in Groovy, the underlying type is a Java ArrayList. This means that it should be resizable, you should be able to initialize it as empty and then dynamically add elements through the add method, like so:
MyType[] list = []
list.add(new MyType(...))
This compiles, however it fails at runtime: No signature of method: [LMyType;.add() is applicable for argument types: (MyType) values: [MyType@383bfa16]
What is the proper way or the proper type to do this?
What you actually created with:
MyType[] list = []
Was fixed size array (not list) with size of 0. You can create fixed size array of size for example 4 with:
MyType[] array = new MyType[4]
But there's no add method of course.
If you create list with def it's something like creating this instance with Object (You can read more about def here). And [] creates empty ArrayList in this case.
So using def list = [] you can then append new items with add() method of ArrayList
list.add(new MyType())
Or more groovy way with overloaded left shift operator:
list << new MyType()
Source: Stackoverflow.com