String.Join with String concatenation: Code Improvement

Question

I currently have a List(Of String) named docIds that looks a bit as follows:

{A3001,A40001,BF0003,13458}

it only contains letters and numbers. I would like to output that array as follows (for use in a DQL Query)

'A3001','A40001','BF0003','13458'

Off course i used the String.Join method

String.Join(",",docIds.ToArray())
Output: A3001,A40001,BF0003,13458

I know of 2 (non-performant) methods to add those quotes

• Method 1: Before the String.Join, iterate every string in list and add the quotes.

• Method 2: The following String operation:

      "'" + String.Join(",",docIds.ToArray()).Replace(",","','") + "'"
  

Question: Is there a more performant/Proper way to achieve the desired result?

Answer 1

You can use LINQ:

string.Join(",", docIds.Select(id => string.Format("'{0}'", id)));

This overload of String.Join was added in .NET 4.0, before you need to add ToArray to create a string[].