title: Find index of a value in an array
body: <p>Can linq somehow be used to find the index of a value in an array?</p>
  
  <p>For instance, this loop locates the key index within an array.</p>
  
  <pre><code>for (int i = 0; i &lt; words.Length; i++)
  {
      if (words[i].IsKey)
      {
          keyIndex = i;
      }
  }
  </code></pre>