How should I concatenate strings?

Question

Are there differences between these examples? Which should I use in which case?

var str1 = \"abc\" + dynamicString + dynamicString2;

var str2 = String.Form         


        

Answer 1

@Xander. I believe you man. However my code shows sb is faster than string.format.

Beat this:

Stopwatch sw = new Stopwatch();
sw.Start();

for (int i = 0; i < 10000; i++)
{
    string r = string.Format("ABC{0}{1}{2}", i, i-10, 
        "dasdkadlkdjakdljadlkjdlkadjalkdj");
}

sw.Stop();
Console.WriteLine("string.format: " + sw.ElapsedTicks);

sw.Reset();
sw.Start();
for (int i = 0; i < 10000; i++)
{
    StringBuilder sb = new StringBuilder();
    string r = sb.AppendFormat("ABC{0}{1}{2}", i, i - 10,
        "dasdkadlkdjakdljadlkjdlkadjalkdj").ToString();
}

sw.Stop();
Console.WriteLine("AppendFormat: " + sw.ElapsedTicks);