SparseArray vs HashMap

Question

I can think of several reasons why HashMaps with integer keys are much better than SparseArrays:

1. The Android documentation for a SparseArray says "It is generally slower than a traditional HashMap".
2. If you write code using HashMaps rather than SparseArrays your code will work with other implementations of Map and you will be able to use all of the Java APIs designed for Maps.
3. If you write code using HashMaps rather than SparseArrays your code will work in non-android projects.
4. Map overrides equals() and hashCode() whereas SparseArray doesn't.

Yet whenever I try to use a HashMap with integer keys in an Android project, IntelliJ tells me I should use a SparseArray instead. I find this really difficult to understand. Does anyone know any compelling reasons for using SparseArrays?

Answer 1

Yet whenever I try to use a HashMap with integer keys in an android project, intelliJ tells me I should use a SparseArray instead.

It is only a warning from this documentation of it sparse array:

It is intended to be more memory efficient than using a HashMap to map Integers to Objects

The SparseArray is made to be memory efficient than using the regular HashMap, that is does not allow multiple gaps within the array not like HashMap. There is nothing to worry about it you can use the traditional HashMap if you desire not worrying about the memory allocation to the device.