How to select a single object using Linq in vb.net
Solution 1
Again, C# code, I'm not sure of I got it right in VB.NET
C#
Customer youngest = customers.Aggregate((c1, c2) => (c1.age < c2.age) ? c1 : c2);
VB.NET
dim youngest = customers.Aggregate( Function(ByVal c1, ByVal c2) IF( (c1.age < c2.age) , c1 , c2 ) );
Solution 2
There is no such operator in regular LINQ which will avoid sorting of the entire IEnumerable
. But you're not the first one who needs a solution. For example check out Jason's answer here (though it's MaxBy
and C# but you'll get an idea): Simple LINQ question in C#
Or MinBy
from MoreLinq
Hucker
Native programming language is C but currently writing code daily in Python, .NET, and SQL Server.
Updated on August 24, 2020Comments
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Hucker over 3 years
I have done a lot of searching to what appears to be a simple LINQ problem but I can't figure out how to do grab an object out of a collection that has a specified minimum (or max value) without resorting to a sort like this:
dim customers= GetCustomers() dim youngest = (From c in customers Order By c.age Ascending).ToList.First
This (untested code) structure works fine with the exception that the entire customer array must be sorted and placed into a list for the only purpose of extracting the first value. That can't be the best way to get the minimum!
Note that I want the whole c record in this case, not the minumum age of a customer that can be done like this (a typical example):
dim customers= GetCustomers() dim youngest = (From c in customers Select c.age).Min
Or even
dim customers= GetCustomers() dim youngest = (From c in customers Select c).Min(Function(x) x.age)
I can't for the life of me figure out how to get the whole object (or even the index) without resorting to the sort...