Comma separated list with “and” in place of the last comma

Question

I want to create a comma separated list in C# with the word \"and\" as last delimiter.

string.Join(\", \", someStringArray)

will result in

Answer 1

One possible solution:

var items = someStringArray; // someStringArray.ToList() if not a ICollection<>
var s = string.Join(", ", items.Take(items.Count() - 1)) +
        (items.Count() > 1 ? " and " : "") + items.LastOrDefault();

Note that this statement can iterate someStringArray multiple times if it doesn't implement ICollection<string> (lists and arrays implement it). If so, create a list with your collection and perform the query on that.

Answer 2

Is there a simple way to achieve it with Linq and without using loops?

Not possible without loop. For loop will work best. LINQ queries will use multiple loops.

    string Combine (IEnumerable<string> list)
    {
        bool start = true;
        var last = string.Empty;
        String str = string.Empty;

        foreach(var item in list)
        {
            if ( !start)
            {
                str = str + " , " + item; 
                last = item;

            }
            else
            {
                str = item;
                start = false;
            } 

        }

        if (!string.IsNullOrWhiteSpace(last))
        {
            str = str.Replace( " , " + last, " and " + last);
        }

        return str;
    }

Answer 3

You can do a Join on all items except the last one and then manually add the last item:

using System;
using System.Linq;

namespace Stackoverflow
{
    class Program
    {
        static void Main(string[] args)
        {
            DumpResult(new string[] { });
            DumpResult(new string[] { "Apple" });
            DumpResult(new string[] { "Apple", "Banana" });
            DumpResult(new string[] { "Apple", "Banana", "Pear" });
        }

        private static void DumpResult(string[] someStringArray)
        {
            string result = string.Join(", ", someStringArray.Take(someStringArray.Length - 1)) + (someStringArray.Length <= 1 ? "" : " and ") + someStringArray.LastOrDefault();
            Console.WriteLine(result);
        }
    }
}

As you can see, there is a check on the amount of items and decides if it's necessary to add the 'and' part.