Hashmap vs Array performance

Question

Is it (performance-wise) better to use Arrays or HashMaps when the indexes of the Array are known? Keep in mind that the \'objects array/map\' in the example is just an exam

Answer 1

arrays when the indexes are know are faster (HashMap uses an array of linked lists behind the scenes which adds a bit of overhead above the array accesses not to mention the hashing operations that need to be done)

and FYI HashMap objects = HashMap(); makes it so you won't have to cast