How do you sort a dictionary by value?

Kalid picture Kalid · Aug 2, 2008 · Viewed 629.9k times · Source

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 it back to the word.

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

Answer

caryden picture caryden · Aug 4, 2008

Use LINQ:

Dictionary<string, int> myDict = new Dictionary<string, int>();
myDict.Add("one", 1);
myDict.Add("four", 4);
myDict.Add("two", 2);
myDict.Add("three", 3);

var sortedDict = from entry in myDict orderby entry.Value ascending select entry;

This would also allow for great flexibility in that you can select the top 10, 20 10%, etc. Or if you are using your word frequency index for type-ahead, you could also include StartsWith clause as well.