C＃中是否有逗号之类的运算符？

Question

Specifically I'd like to run the code below. The problem is unlike C and JS which has a comma operator ( i=(1,2) is 2) C# doesn't. AddRange does not return the list it's using so I'm stuck on this lambda. How do I write the lambda without using braces and return statement like the code under it?

var ls1 = new String[]{"one", "three"};
var ls2 = new String[]{"two", "four"};
var ls = (new[] {ls1, ls2}).Aggregate(new List<String>(), (l,r)=> (l.AddRange(r), l));
//var ls = (new[] {ls1, ls2}).Aggregate(new List<String>(), (l,r)=> {l.AddRange(r); return l;});
Console.WriteLine(string.Join(", ", ls));

Answer 1

Will extension method work for you? It is not like (1,2) operator, but achieves goal of avoiding return in lambda

public static class Ext
{
    public static List<string> AddRangeAndReturn(this List<string> list, IEnumerable<string> itemsToAdd)
    {
        list.AddRange(itemsToAdd);

        return list;
    }
}

Example of use:

var ls = (new[] {ls1, ls2}).Aggregate(new List<String>(), (l,r)=> l.AddRangeWithReturn(r) );