Problem in one of the methods

[ghost]

There is a problem with this line
return result.stream().mapToInt(i -> i).toArray();
i is not declared anywhere. What is its meaning ?

[technobium]

Hi,

Thanks for the comment. This is a valid method to convert the ArrayList to an array of int's. The "i" is inside the lambada expression and it is valid. It may be misleading because it has the same name as the "for (int i " variable. It could have been:

return result.stream().mapToInt(x -> x).toArray();

https://docs.oracle.com/javase/8/docs/api/java/util/stream/Stream.html

Hope this helps.

Best regards