android memory tips

There's SparseArray but there are also classes for each of the individual primitive types. There's a SparseBooleanArray, a SparseIntArray and so on. Deciding whether to use these Android specific collection classes is a matter of performance and memory management. For example, the SparseArray class manages memory more efficiently than HashMap for the reasons I described. When you use SparseArray, you don't have to box the keys. That is, you don't have to wrap primitives in objects.