I have come across a class that has an immutable property: MyObject[] allObjs The property is initialized like this: List<MyObject> objs = createAllMyObjects(); allObjs = objs.toArray(new MyObject[objs.size()]); When it is exposed through the accessor, it's done as a List: public List<MyObject> getAllMyObjects() { return Collections.unmodifiableList(Arrays.asList(allObjs)); } Why would a programmer do this? Is there a benefit that I don't know about? Performance is not a concern, as the array of objs will only ever number in a few dozen elements. It seems that we are going round and round in circles. The class is a sort of factory, so it's got a private constructor and exposes only static methods (not sure if this could be a reason for the madness).