title: A function to convert null to string
body: <p>I want to create a function to convert any null value e.g. from a database to an empty string.
  I know there are methods such as if <code>value != null ?? value : String.Empty</code> but is there a way to pass <code>null</code> to a method e.g.</p>
  
  <pre><code>public string nullToString(string? value)
  {
      if(value == null) return empty;
      return value
  }
  </code></pre>
  
  <p>But I am not sure on the parameter syntax to do this..</p>
  
  <p>I tried the above but it says not a nullable type.</p>
  
  <p>Thanks in advance.</p>