Converting IEnumerable to a Comma-Delimited String
I’m not sure whether it’s the fastest way to convert an enumerable collection of longs or ints to a comma-delimited list in C#, but it might be the shortest.
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IEnumerable<long> ids = new long[]{1,3,4,5};
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string delimitedIds = string.Join(",", ids.Select(x => x.ToString()).ToArray());
If you need a LINQ-free version for backward compatibility, check out Missing Functions on IEnumerable on Steve Cooper’s blog.
Hi. Thanks for the mention! I’ve found that Join is so useful on IEnumerable, I’ve written an extension function which has this signature;
string Join(this IEnumerable sequence, string seperator);
which means you can write;
string delimitedids = ids.Select(x => x.ToString()).Join(“, “);
Here’s the implementation using a stringbuilder;
public static string Join(this IEnumerable strings, string seperator)
{
IEnumerator en = strings.GetEnumerator();
StringBuilder sb = new StringBuilder();
if (en.MoveNext())
{
// we have at least one item.
sb.Append(en.Current);
}
while (en.MoveNext())
{
// second and subsequent get delimiter
sb.Append(seperator).Append(en.Current);
}
return sb.ToString();
}
I tend to use this all the time when putting together code that generates descriptions; debug messages, ToStrings, that kind of thing.