String output: format or concat in C#?

Question

Let\'s say that you want to output or concat strings. Which of the following styles do you prefer?

• var p = new { FirstName = \"Bill\", LastName = \"Ga

Answer 1

Oh dear - after reading one of the other replies I tried reversing the order of the operations - so performing the concatenation first, then the String.Format...

Bill Gates
Console.WriteLine(p.FirstName + " " + p.LastName); took: 8ms - 30488 ticks
Bill Gates
Console.WriteLine("{0} {1}", p.FirstName, p.LastName); took: 0ms - 182 ticks

So the order of the operations makes a HUGE difference, or rather the very first operation is ALWAYS much slower.

Here is the results of a run where operations are completed more than once. I have tried changing the orders but things generally follow the same rules, once the first result is ignored:

Bill Gates
Console.WriteLine(FirstName + " " + LastName); took: 5ms - 20335 ticks
Bill Gates
Console.WriteLine(FirstName + " " + LastName); took: 0ms - 156 ticks
Bill Gates
Console.WriteLine(FirstName + " " + LastName); took: 0ms - 122 ticks
Bill Gates
Console.WriteLine("{0} {1}", FirstName, LastName); took: 0ms - 181 ticks
Bill Gates
Console.WriteLine("{0} {1}", FirstName, LastName); took: 0ms - 122 ticks
Bill Gates
String.Concat(FirstName, " ", LastName); took: 0ms - 142 ticks
Bill Gates
String.Concat(FirstName, " ", LastName); took: 0ms - 117 ticks

As you can see subsequent runs of the same method (I refactored the code into 3 methods) are incrementally faster. The fastest appears to be the Console.WriteLine(String.Concat(...)) method, followed by normal concatenation, and then the formatted operations.

The initial delay in startup is likely the initialisation of Console Stream, as placing a Console.Writeline("Start!") before the first operation brings all times back into line.