Question

I’m having some trouble to do the following:

int[] tmpIntList = (int[])MyArrayList.toArray(someValue);

MyArrayList contains only numbers. I get a typecast error since ArrayList only returns Object[] but why isnt it possible to turn it into a int[] ?

Answer 1

An ArrayList can’t contain int values, as it’s backed by an Object[] (even when appropriately generic).

The closest you could come would be to have an Integer[] – which can’t be cast to an int[]. You have to convert each element separately. I believe there are libraries which implement these conversions for all the primitive types.

Basically the problem is that Java generics don’t support primitive types.