C# How do I combine values in a list of name value pairs that have the same name?

Question

I have a list that contains name/value pairs

Class looks like this:

string Name { get; set; }
string Value { get; set; }

What I need to do is concatenate all of the values that have the same name into a new list where the class looks like this:

string Name { get; set; }
list<string> Values { get; set; }

Think you might want to look at this: [ToLookup()](https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.tolookup?view=netframework-4.7.2). — John Wu, Jan 31 '19 at 23:09
`var combined = nvpList.GroupBy(nvp => nvp.Name).Select(group => new NameValueClass {Name = group.Key, Values = group.SelectMany(nvp => nvp.Values).Distinct().ToList()});` — Rufus L, Jan 31 '19 at 23:26
Rufus you saved the day. This is EXACTLY what I was looking for. Thank you! — Scott Boyte, Feb 01 '19 at 00:40

score 1 · Answer 1 · edited Jan 31 '19 at 23:15

1

You can use LINQ GroupBy method:

var result = yourList.GroupBy(x => x.Name, x => x.Value, 
    (k, g) => new YouSecondClass { Name = key, Values = g.ToList() });

edited Jan 31 '19 at 23:15

Carlos Muñoz

answered Jan 31 '19 at 23:01

Kirill Polishchuk

1 Answers1