Hashmap 与 Android 中的 Bundle 效率和性能比较

Question

I am trying to understand the performance impact of using a HashMap vs a Bundle in an Android program. I understand that a Bundle is a specialized Android component - does it therefore make it superior to a HashMap if one needed to simply store basic data types ( Integer s, String s etc.) and not complex objects?

Answer 1

Bundle s are actually built on top of ArrayMap s, which are memory-efficient implementations of Map s. For smaller ArrayMap s, a search takes less computational time than computing the hash for a similarly populated HashMap . But if you have more than a few hundred items in it, the HashMap will perform better.

Besides, Bundle s were not designed to be general-purpose data structures.

Answer 2

Bundle allows to put String, integer, boolean, etc. into it but a HashMap allows only string, for others you have to convert them to/from objects.

One more difference is that with a Bundle, every object it contain is parcelable. This allows Bundles to be used as service parameters and to be attached to intents or fragments to passed into activities or fragments.