Question

I want to turn an array or list of ints into a comma delimited string, like this:

string myFunction(List<int> a) {
    return string.Join(",", a);
}

But string.Join only takes List<string> as the second parameter. What is the best way to do this?

Answer 1

The best way is to upgrade to .NET 4.0 or later where there is an overload that does what you want:

• String.Join<T>(String, IEnumerable<T>)

If you can’t upgrade, you can achieve the same effect using Select and ToArray.

    return String.Join(",", a.Select(x => x.ToString()).ToArray());