I found this code on SO to map strings to ints

```
Arrays.stream(myarray).mapToInt(Integer::parseInt).toArray();

```

But how do I make it map to Integer type not the primitive int?

I tried switching from `Integer.parseInt` to `Integer.valueOf`, but it seems that the `mapToInt()` method forces the primitive type.

I have an ArrayList of arrays of Integers, so I cannot use primitive ints.