title: Regex to find words with specific character
body: <p>How to find all words which contain a specific letter in it?</p>
  
  <p>For example, if my string is </p>
  
  <pre><code>This is a Station called South Yarra
  </code></pre>
  
  <p>then I want to extract all words with the letter 'a' in them. The matches will be </p>
  
  <pre><code>"a", "Station", "called", "Yarra"
  </code></pre>
  
  <p>So far I have tried</p>
  
  <pre><code>Regex regex = new Regex(@"\w[a]\w");
  
  Regex regex = new Regex(@"\s[a*]\s");
  </code></pre>