title: How to handle nullable string as a function parameter
body: <p>I have function with parameters as given below.</p>
  
  <pre><code>public void myfunction(int a, string b){}
  </code></pre>
  
  <p>Can we call this function by passing only first parameter and second parameter is optional(nullable string)?</p>
  
  <pre><code>myfunction(5);
  </code></pre>
  
  <p>If yes then how.</p>