Is it possible to return the object with the minimal property in a list?

Question

My solution is

class Test
{
    public int X;
}    

class Program
{
    static void Main(string[] args)
    {
        var arr = new List<Test>();

        var min = arr.Min(x => x.X);
        Test a = arr.First(y => y.X == min);
    }
}

Can this be done in just one-line (only iterating the list once instead of twice)?

You could order the list and then retrieve the first one. Something like: .OrderBy(x => x.X).First(); — Shion, Aug 27 '15 at 10:40
@YuvalItzchakov No, he is retrieving the minimum `x`, not the object with the minimum `x`. — Maarten, Aug 27 '15 at 10:42

score 2 · Answer 1 · edited May 23 '17 at 10:27

2

why not just order the sequence by the property you want in ascending order and get the first item?

arr.OrderBy(x => x.X).FirstOrDefault();

I just find this and this is a duplicate question

edited May 23 '17 at 10:27

Community

1
1

answered Aug 27 '15 at 10:43

Hamid Pourjam

20,441
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cool, but sorting the list is slower than looking up the array twice.... – justyy Aug 27 '15 at 10:44

score 2 · Accepted Answer · answered Aug 27 '15 at 10:47

There's a popular extension to linq in "MoreLinq" which provides a "MinBy" method:

https://www.nuget.org/packages/MoreLinq.Source.MoreEnumerable.MinBy/

Using that, your code would become:

Test a = arr.MinBy(item => item.X);

Also see https://www.nuget.org/packages?q=id%3Amorelinq

We routinely use the extensions from MoreLinq in many of our projects - it's definitely worth. (Originally written by Jon Skeet and others, I believe.)

score 0 · Answer 3 · answered Aug 27 '15 at 10:48

In the question you want a single iteration, and in response to @dotctor you say that the performance of his solution is worse, thereby saying that performance is important too. Which is more important, performance, or the single iteration?

In this case you can have what you want, but you have to do it without Linq. Loop through the data, and remember the object with the lowest value of X.

var arr = new List<Test>();
Test minimum = null;
foreach (var x in arr) {
    if (minimum == null || x.X < minimum.X) {
        minimum = x;
    }
}
// minimum now contains the object with the lowest value of X.

Is it possible to return the object with the minimal property in a list?

3 Answers3