是否有必要为不可变对象制作深层副本

Question

是否有理由对不可变对象的引用数组进行深层复制？

Answer 1

No. A (shallow) copy of the array will have all the references to the immutable objects at the time of the copying. No matter what happens with the original array, the copy will always have the same state as at the time of the copying.

Deep copying of immutable objects (or arrays of immutable objects) would make sense only if you wanted to have two equal but distinct immutable objects.