Question

Imagine you got a class like this:

class Foo {
    string key;
    int value;
}

How would you select the Foo with the highest value from an IEnumeralbe<Foo>?

A basic problem is to keep the number of iterations low (i.e. at 1), but that affects readability. After all, the best I could find was something along the lines of this:

IEnumerable<Foo> list;
Foo max = list.Aggregate ((l, r) => l.value > r.value ? l : r);

Can you think of a more better way?

Edit: list.OrderByDescending(l => l.value).First(); was my preferred option, but it is not O(n).

Answer 1

You can grab the MaxBy LINQ extension method from Jon Skeet’s MoreLinq project. Then it’s just:

Foo max = list.MaxBy(f => f.value);