How to convert Guid[] to String?

Question

Something like String.Join(",", new string[] { "a", "b" });, but for Guid[]

var guids = new Guid[] { Guid.Empty, Guid.Empty };

var str = /* Magic */

// str = 00000000-0000-0000-0000-000000000000,00000000-0000-0000-0000-000000000000

Answer 1

I thought this would work?

StringBuilder stringBuilder = new StringBuilder();
int i = 0;
foreach (var guid in guids)
{
    stringBuilder.Append(guid.ToString());
    if (++i < guids.Length)
    { 
        stringBuilder.Append(","); 
    }
}

var str = stringBuilder.ToString();

Answer 2

var str = guids.Select(g => g.ToString())
               .Aggregate((working, next) => working + "," + next);

Once your list of Guids starts growing, this method of concatenation is going to cause performance issues. You can modify it to use a StringBuilder:

var str = guids.Select(g => g.ToString())
               .Aggregate(new StringBuilder(),
                          (sb, str) => sb.Append("," + str),
                          sb => sb.ToString());

Both of those are the complicated LINQ Extension method way of doing things. You could also simply use String.Join:

var str = String.Join(",", guids.Select(g => g.ToString()).ToArray());

Answer 3

String.Join(",", guids.Select(g => g.ToString()).ToArray());

Answer 4

if your framework >= .NET 3.5

String.Join(",", (from g in guids select g.ToString()).ToArray())

Answer 5

.NET 4 added a String.Join<T>(string separator, IEnumerable<T> values method. So, in .NET 4, just this will work:

String.Join(",", guids);

Answer 6

String.Join(",", Array.ConvertAll(guids, g => g.ToString()));