If we look at the core of this question, it has to do with an array not finding duplicates. The goal here is to be able to remove duplicates from an integer array without using any collection API class libraries. Several levels of interview questions will come up to test your knowledge of basic to complex problem-solving solutions. This one sits somewhere in the middle of the pack. When an interviewer asks whether or not you need a loop or recursion (depending on your skill level), she/he is asking the order in which elements are inserted in a Set. Answering with something like 'An array is a static fixed-length structure that cannot change its length' is probably something that will tell the interviewer that you have a solid understanding of how deleting an array works.