How to find the key which has the highest value in a c# dictionary?

Question

I have a Dictionary and I want to find the key which has the highest value.

For example if I had

Key  |  Value
a    |   1
b    |   2
c    |   3

I would want c to be returned.

I have this at the moment but it only searches for the highest value, I'm not sure how to return the key.

var max = occurrences.Max(x => x.Value);

score 9 · Accepted Answer · answered May 12 '17 at 06:24

9

var maxKey = occurrences.OrderByDescending(x => x.Value).First().Key;

answered May 12 '17 at 06:24

DDan

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score 5 · Answer 2 · answered May 12 '17 at 06:20

5

You need to include MoreLinq and use MaxBy

var result = occurrences.MaxBy(kvp => kvp.Value).Key;

answered May 12 '17 at 06:20

Sajeetharan

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1

This is great! MoreLinq sound cool! I didn't know about this. Well played! – DDan May 12 '17 at 06:28
1

Me too didnt know there is a library MoreLinq. Good to know – Jins Peter May 12 '17 at 06:29

score 0 · Answer 3 · answered May 12 '17 at 06:34

0

        var dict = new Dictionary<string,int>();
        dict.Add("a",1);
        dict.Add("b",2);
        dict.Add("c",3);

        var max= dict.OrderByDescending(x => x.Value).FirstOrDefault();

Remember to check if max is null.

answered May 12 '17 at 06:34

gatsby

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score 0 · Answer 4 · answered May 12 '17 at 06:37

Also here is a solution that consider if there were more than one key with the max value in the dictionary?

Dictionary<char, int> dic = new Dictionary<char, int>();
dic.Add('a', 1);
dic.Add('b', 2);
dic.Add('c', 3);
dic.Add('d', 3);

var maxValue = (int)dic.Max(i => i.Value);

List<char> maxKeys = dic.Where(i => i.Value == maxValue).Select(i => i.Key).ToList();

How to find the key which has the highest value in a c# dictionary?

4 Answers4