title: Why does StringBuilder have a default capacity of 16 characters?
body: <p>Why does StringBuilder have a default capacity of 16 characters? Is this some kind of optimization?</p>
  
  <pre><code>StringBuilder builder = new StringBuilder();
  Console.WriteLine("builder capacity: '{0}'", builder.Capacity);
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>builder capacity: '16'
  </code></pre>