How to build a histogram for a list of int in C#

c#, linq

Solution

 int highestAppearanceNum = demoList.GroupBy(i => i)
            .OrderByDescending(grp => grp.Count())
            .Select(grp => grp.First())
            .First();

Edit: If you also want to know which number appears how often:

var appearances = demoList.GroupBy(i => i)
    .OrderByDescending(grp => grp.Count())
    .Select(grp => new { Num = grp.Key, Count = grp.Count() });
if (appearances.Any())
{
    int highestAppearanceNum = appearances.First().Num;     // 1
    int highestAppearanceCount = appearances.First().Count; // 5
}

Problem

Possible Duplicate: Find the most frequent numbers in an array using LINQ I have a list of int, `List<int> demoList`, which is something like `{1, 2, 1, 1, 1, 3, 2, 1}` and I want to write a LINQ statement for obtaining the number with the highest number of appearences from that list, which in my case is `1`.

Original source

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