title: .net regular expression returning 2 results where I only want 1
body: <p>Trying to extract a US phone number (in any format) from mixed character value, returning only ONE or ZERO results with .NET regular expression. </p>
  
  <blockquote>
    <p><strong>Example:</strong>  yyy666 555 5555yyyy1</p>
  </blockquote>
  
  <p>The pattern <code>(?&lt;!\d)\(?([\d]{3})*\)?[\s-]?[\d]{3}[\s-]?[\d]{4}(?!\d)</code> is returning:</p>
  
  <blockquote>
    <p>"666 555 5555", "666". </p>
  </blockquote>
  
  <p>I do not want the second result "666" (which contains only the area code), there should only be ONE result or ZERO Results (IE. the return for that example should only be a full phone number "666 555 5555" or nothing).</p>
  
  <p>What am I missing/how do I make it return 0 or 1 results?</p>