Question

I often have to sort a dictionary (consisting of keys & values) by value. For example, I have a hash of words and respective frequencies that I want to order by frequency.

There is a SortedList which is good for a single value (say frequency), that I want to map back to the word.

SortedDictionary orders by key, not value. Some resort to a custom class, but is there a cleaner way?

Answer 1

Use:

using System.Linq.Enumerable; ... List<KeyValuePair<string, string>> myList = aDictionary.ToList();  myList.Sort(     delegate(KeyValuePair<string, string> pair1,     KeyValuePair<string, string> pair2)     {         return pair1.Value.CompareTo(pair2.Value);     } ); 

Since you’re targeting .NET 2.0 or above, you can simplify this into lambda syntax — it’s equivalent, but shorter. If you’re targeting .NET 2.0 you can only use this syntax if you’re using the compiler from Visual Studio 2008 (or above).

var myList = aDictionary.ToList();  myList.Sort((pair1,pair2) => pair1.Value.CompareTo(pair2.Value));