Am I undermining the efficiency of StringBuilder?

Question

I've started using StringBuilder in preference to straight concatenation, but it seems like it's missing a crucial method. So, I implemented it myself, as an extension:

public void Append(this StringBuilder stringBuilder, params string[] args) {     foreach (string arg in args)         stringBuilder.Append(arg); } 

This turns the following mess:

StringBuilder sb = new StringBuilder(); ... sb.Append(SettingNode); sb.Append(KeyAttribute); sb.Append(setting.Name); 

Into this:

sb.Append(SettingNode, KeyAttribute, setting.Name); 

I could use sb.AppendFormat("{0}{1}{2}",..., but this seems even less preferred, and still harder to read. Is my extension a good method, or does it somehow undermine the benefits of StringBuilder? I'm not trying to prematurely optimize anything, as my method is more about readability than speed, but I'd also like to know I'm not shooting myself in the foot.

Answer 1

I see no problem with your extension. If it works for you it's all good.

I myself prefere:

sb.Append(SettingNode)   .Append(KeyAttribute)   .Append(setting.Name); 

Answer 2

Questions like this can always be answered with a simple test case.

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Diagnostics;  namespace SBTest {     class Program     {         private const int ITERATIONS = 1000000;          private static void Main(string[] args)         {             Test1();             Test2();             Test3();         }          private static void Test1()         {             var sw = Stopwatch.StartNew();             var sb = new StringBuilder();              for (var i = 0; i < ITERATIONS; i++)             {                 sb.Append("TEST" + i.ToString("00000"),                           "TEST" + (i + 1).ToString("00000"),                           "TEST" + (i + 2).ToString("00000"));             }              sw.Stop();             Console.WriteLine("Testing Append() extension method...");             Console.WriteLine("--------------------------------------------");             Console.WriteLine("Test 1 iterations: {0:n0}", ITERATIONS);             Console.WriteLine("Test 1 milliseconds: {0:n0}", sw.ElapsedMilliseconds);             Console.WriteLine("Test 1 output length: {0:n0}", sb.Length);             Console.WriteLine("");         }          private static void Test2()         {             var sw = Stopwatch.StartNew();             var sb = new StringBuilder();              for (var i = 0; i < ITERATIONS; i++)             {                 sb.Append("TEST" + i.ToString("00000"));                 sb.Append("TEST" + (i+1).ToString("00000"));                 sb.Append("TEST" + (i+2).ToString("00000"));             }              sw.Stop();                 Console.WriteLine("Testing multiple calls to Append() built-in method...");             Console.WriteLine("--------------------------------------------");             Console.WriteLine("Test 2 iterations: {0:n0}", ITERATIONS);             Console.WriteLine("Test 2 milliseconds: {0:n0}", sw.ElapsedMilliseconds);             Console.WriteLine("Test 2 output length: {0:n0}", sb.Length);             Console.WriteLine("");         }          private static void Test3()         {             var sw = Stopwatch.StartNew();             var sb = new StringBuilder();              for (var i = 0; i < ITERATIONS; i++)             {                 sb.AppendFormat("{0}{1}{2}",                     "TEST" + i.ToString("00000"),                     "TEST" + (i + 1).ToString("00000"),                     "TEST" + (i + 2).ToString("00000"));             }              sw.Stop();             Console.WriteLine("Testing AppendFormat() built-in method...");             Console.WriteLine("--------------------------------------------");                         Console.WriteLine("Test 3 iterations: {0:n0}", ITERATIONS);             Console.WriteLine("Test 3 milliseconds: {0:n0}", sw.ElapsedMilliseconds);             Console.WriteLine("Test 3 output length: {0:n0}", sb.Length);             Console.WriteLine("");         }     }      public static class SBExtentions     {         public static void Append(this StringBuilder sb, params string[] args)         {             foreach (var arg in args)                 sb.Append(arg);         }     } } 

On my PC, the output is:

Testing Append() extension method... -------------------------------------------- Test 1 iterations: 1,000,000 Test 1 milliseconds: 1,080 Test 1 output length: 29,700,006  Testing multiple calls to Append() built-in method... -------------------------------------------- Test 2 iterations: 1,000,000 Test 2 milliseconds: 1,001 Test 2 output length: 29,700,006  Testing AppendFormat() built-in method... -------------------------------------------- Test 3 iterations: 1,000,000 Test 3 milliseconds: 1,124 Test 3 output length: 29,700,006 

So your extension method is only slightly slower than the Append() method and is slightly faster than the AppendFormat() method, but in all 3 cases, the difference is entirely too trivial to worry about. Thus, if your extension method enhances the readability of your code, use it!