How to sort strings so strings that start with a search term are at first?

Question

I have a big list of strings. I am currently handling a search by doing a

.Where(x => x.Contains(search)).ToArray()

This gets all of the results I want, but in a poor order. For example a search for "ch" could come up with:

Potato Starch
Chicken

Since they both contain ch, I want them to both show up, but I want Chicken to be first in the array since it starts with ch.

What are some ways I could go about reordering my results so strings that start with the search string are at the start of the array?

Answer 1

You can order by the index, thus having strings starting with the search at the beginning:

.Where(x => x.Contains(search)).OrderBy(x => x.IndexOf(search)).ToArray()

Answer 2

You can add a simple OrderBy field that places the relevant results at the top:

.Where(x => x.Contains(search))
.OrderBy(x => x.StartsWith(search) ? 0 : 1)
.ThenBy(x => x)
.ToArray()

Note that if this is a database query (Linq to SQL/entities), you'll need to enumerate the results first, as the engine won't know how to translate it to SQL:

.Where(x => x.Contains(search))
.AsEnumerable()
.OrderBy(x => x.StartsWith(search) ? 0 : 1)
.ThenBy(x => x)
.ToArray()