Arion Arion - 2 months ago 17
C# Question

Linq: How to get second last

So i have a List of strings that looks like this:

var ls=new List<string>()
{
"100",
"101-102-1002",
"105-153-1532-1532",
"105-1854-45-198",
"180-95-45-200"
};


I want to get the second last of the the split string. So my output looks like this:

null,
102,
1532,
45,
45


I have a solution for it that looks like this:

ls.Select (l =>l.Split('-').Select ((s,i) =>new {s,i})
.OrderByDescending (x=>x.i).Skip(1).Take(1))


I think that this solution might be to complex for this simple task. So my question is: Do any of you have a simpler solution to this problem?

Answer

Reverse fits well here:

ls.SelectMany(l =>l.Split('-').Reverse().Skip(1).Take(1).DefaultIfEmpty())

I also use SelectMany to transform IEnumerable<IEnumerable<string>> to <IEnumerable<string>.

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