Format string but omit an argument if it is null
<p>I have a situation in production code, please see the following code snippet to visualize.</p>

<pre><code>string formatStr = "{2} (FC {3:D3}): {1} {0}";
object obj= null;
string str = string.Format(formatStr, "", "10 - 15","Blabla", obj);
</code></pre>

<p>Output of this is going to be "Blabla (FC ): 10 - 15 "</p>

<p>Observe that there is no associated value with FC cause the obj was null, I don't want to print FC with nothing in it. </p>

<p>So what I till now thought was to inspect obj and remove the (FC {3:D3}): from it if obj is null, is there any other technique where I don't have to do this.</p>