Does Distinct() preserve always take the first element in the list

Question

Would

int[] nums = { 2, 3, 3, 4, 2, 1, 6, 7, 10 };
var distinct = nums.Distinct();

always return 2, 3, 4, 1, 6, 7, 10 in that order?

Answer 1

The defined behavior of Enumerable.Distinct is that it will return an unordered collection (Documentation).

However the current implementation of Distinct in Linq to Objects will preserve order. This is not guaranteed for other LINQ providers though and the behavior should not be relied upon.

Answer 2

I think the word "unordered" means the same order of the original sequence.
Hence, the caller should decide whether to sort the result or not.