title: C# error: operator '!=' cannot be applied to operands of type 'char' and 'string'
body: <p>Today, following a tutorial from a book (literally) I got an unexpected error:</p>
  
  <pre><code>operator '!=' cannot be applied to operands of type 'char' and 'string'
  </code></pre>
  
  <p>in this part of code:</p>
  
  <pre><code>public void displayFullName()
  {
      StringBuilder FullName = new StringBuilder();
  
      FullName.Append(firstName);
      FullName.Append(" ");
      if (middleName[0] != "") //ERROR occurs here
      {
          FullName.Append(middleName[0]);
          FullName.Append(". ");
      }
      FullName.Append(lastName);
  
      Console.WriteLine(FullName);
  }
  </code></pre>
  
  <p>where of course middleName is declared as: </p>
  
  <pre><code>    class Person
  {
      private string firstName;
      private string middleName; //obiously declared as string
      private string lastName;
      private int age;
  (...the rest of code...)
  </code></pre>
  
  <p>So, the question is how would you resolve this error?</p>