title: Check if XML-node has attribute with Linq C#?
body: <p>How can I check and see if a node actually has a certain attribute? I have an XML-file containing several nodes looking like this:</p>
  
  <pre><code>&lt;Field From="OldString" To="NewString" /&gt; 
  </code></pre>
  
  <p>So far so good. The problem is that this structure is about to be changed to that some nodes will look like this:</p>
  
  <pre><code>&lt;Field From="OldString" To="NewString" PrefixValue="OptionalAttribute" /&gt;
  </code></pre>
  
  <p>Now, when the PrefixValue is present I am supposed to prepend the value in that attribute to a string, and that is not very difficult, but I have run into some problems when I try to see if the PrefixValue attribute is present at all for a node. In the instances where no PrefixValue is present, the attribute PrefixValue will not exist in the node at all. How would I go about checking to see if the attribute exists with a Linq-expression?</p>