[ilammy]

They are deterministic in the sense that provided everything else is the same, iteration order would be the same after each insertion.

However, it can change after insertion (if the hash bucket count changes). If the hash function is random-keyed, iteration order would be different for different instances of the hash table even if you insert the same items in the same order.

Sometimes you want the order to be consistent every time. Be it insertion order, or some natural order of the items.