title: What is the difference between a class having private constructor and a sealed class having private constructor?
body: <p>Is there any difference between A and B?</p>
  
  <p>Class A has private constructor:</p>
  
  <pre><code>class A
  {
      private A()
      { }
  }
  </code></pre>
  
  <p>Class B is sealed and has a private constructor:</p>
  
  <pre><code>sealed class B
  {
      private B()
      { }
  }
  </code></pre>