CODEWITHSUNDEEP
c#.net
Luke
Luke

Reputation: 1806

How to get the smallest date from a list of objects with a date?

I created a simple class that represents a project:

public class EntityAuftrag
{
    public string cis_auftrag { get; set; }
    public string bezeich { get; set; }
    public DateTime? dStart { get; set; }
    public DateTime? dEnd { get; set; }
    public decimal? aufstunde { get; set; }
    public int id_auftrag { get; set; }
    public string barcolor { get; set; }
}

Now I have a list of these. I want to extract the smallest date, how do I do that?

Upvotes: 18

Views: 47880

Answers (3)

Tim Schmelter
Tim Schmelter

Reputation: 460068

You can use Enumerable.Min (null values will be ignored unless all values are null):

DateTime? smallest = auftragList.Min(a => a.dStart);

Edit: if you want to find the object with the earliest(start) date, you can use OrderBy and First:

EntityAuftrag auft = auftragList.OrderBy(a => a.dStart).First();

If you want the latest date, you can use Enumerable.OrderByDescending instead.

Upvotes: 48

Kris Selbekk
Kris Selbekk

Reputation: 7614

You can do that simply with Linq. Given that you want the object with the earliest dStart, you can do the following:

List<EntityAuftrag> list = someSourceOfItems;

EntityAuftrag firstObject = list.OrderBy( i => i.dStart ).First() as EntityAuftrag;

Alternatively (not sure if the above is the right syntax), you can do it this way:

List<EntityAuftrag> list = someSourceOfItems;

EntityAuftrag firstObject = (from item in list
                            orderby item.dStart
                            select item).Single() as EntityAuftrag;

Enjoy your day :-)

Upvotes: 3

Tamir
Tamir

Reputation: 3901

you can use the Min() LINQ extension method:

collection.Min(item => item.dStart);

I see your date property is nullable, so if you want to avoid nulls, use the following:

collection.Where(item=> dStart.HasValue).Min(item => item.dStart);

Upvotes: 4

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