Sort a C# list by word

Question

I want to sort a C# list by word. Assume I have a C# list (of objects) which contains following words:

[{id:1, name: "ABC"},
 {id:2, name: "XXX"},
 {id:3, name: "Mille"},
 {id:4, name: "YYY"},
 {id:5, name: "Mill",
 {id:6, name: "Millen"},
 {id:7, name: "OOO"},
 {id:8, name: "GGGG"},
 {id:9, name: null},
 {id:10, name: "XXX"},
 {id:11, name: "mil"}]  

If user pass Mil as a search key, I want to return all the words starting with the search key & then all the words which does not match criteria & have them sort alphabetically.

Easiest way I can think of is to run a for loop over the result set, put all the words starting with search key into one list and put the renaming words into another list. Sort the second list and them combine both the list to return the result.

I wonder if there is a smarter or inbuilt way to get the desired result.

Answer 1

Sure! You will sort by the presence of a match, then by the name, like this:

var results = objects.OrderByDescending(o => o.Name.StartsWith(searchKey))
                     .ThenBy(o => o.Name);

Note that false comes before true in a sort, so you'll need to use OrderByDescending.

As AlexD points out, the name can be null. You'll have to decide how you want to treat this. The easiest way would be to use o.Name?.StartsWith(searchKey) ?? false, but you'll have to decide based on your needs. Also, not all Linq scenarios support null propagation (Linq To Entities comes to mind).