title: Why this Javascript RegExp is returning true?
body: <p>I need to validate alpha characters (in a request, node.js) and what i used was:</p>
  
  <pre><code>/[a-zA-Z]+/.test(input)
  </code></pre>
  
  <p>BUT when a value null was passed, then it was validated OK (regexp returns TRUE)
  example:</p>
  
  <pre><code>/[a-zA-Z]+/.test(null) // &lt;--- this returns true :(
  </code></pre>
  
  <p>Somebody can explain me this? i need to avoid nulls, thanks!</p>