How to sort the list of objects by the values coming from array?

Question

I have a List products; with 100+ items.

For each item from the list I have product id.

And I have an array int[] sortedArray = {3,6,22,98,6,45,87};

I have to sort my product list and make order by productid, how it is in sortedArray. How can I implement that?

Thanks in Advance!

What is in `sortedArray`? Is it indices, or product IDs? – Matthew Watson Jan 27 '20 at 12:05 — Matthew Watson, Jan 27 '20 at 12:05

Mihai Alexandru-Ionut · Answer 1 · 2020-01-27T12:05:51.707

2

One possible approach could be using OrderBy method by passing a Func which uses IndexOf method in order to sort the list based on the sortedArray.

list.OrderBy(s => sortedArray.IndexOf(s.ProductId)).ToList();

edited Jan 27 '20 at 12:05

answered Jan 27 '20 at 11:59

Mihai Alexandru-Ionut

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Watch out though - this is an `O(N^2.Log(N))` operation which is going to be nasty on large data sets. – Matthew Watson Jan 27 '20 at 12:10
@MatthewWatson, Then we could create a hash structure or dictionary in order to access the element with `O(1)` – Mihai Alexandru-Ionut Jan 27 '20 at 12:12

How to sort the list of objects by the values coming from array?

1 Answers1