Question

My static method returns the following concatenated string like this

return (Sb.ToString() + " " + ds.Tables[1].Rows[0].ItemArray[0].ToString() + " " + ds.Tables[2].Rows[0].ItemArray[0].ToString());

Is this a good/bad practise or should i use stringbuilder for it….

Answer 1

String concatenation in a single shot will be faster than using a StringBuilder – although if Sb is already a StringBuilder, it might make sense to append to that instead (assuming it’s a local variable). Assuming this is actually data which has come from a database, the time taken to fetch it is going to vastly exceed the string concatenation here anyway.

Note that you don’t need all these calls to ToString() – this would do just as well:

return (Sb + " " + ds.Tables[1].Rows[0].ItemArray[0] + " " + 
        ds.Tables[2].Rows[0].ItemArray[0]);

Here’s the equivalent using the existing builder:

return Sb.Append(" ")
         .Append(ds.Tables[1].Rows[0].ItemArray[0])
         .Append(" ")
         .Append(ds.Tables[2].Rows[0].ItemArray[0])
         .ToString();

This might be slightly faster – it will depend on various things. Personally I’d probably use the concatenation version anyway, as it’s slightly simpler IMO. I highly doubt that you’d see much difference in performance. Note that this is a bit of a special case, as you’ve already got a StringBuilder; in the general case of concatenating a set of items where they can all be specified in one compile-time expression, concatenation can be faster as a single method call can provide all the required information.

I have a page on StringBuilder vs string concatenation if you want more details and guidelines.