title: A-Za-z vs. a-z/i case insensitive
body: <p>What is considered best practice, and what is the fastest to compute?</p>
  
  <pre><code>[A-Za-z]
  </code></pre>
  
  <p>vs.</p>
  
  <pre><code>[a-z]/i
  </code></pre>
  
  <p>Assuming that you don't care about the rest of the regex's case. I'm wanting to know with exactly those 2 regex's which is the fastest. Or does it yield the same outcome under the hood.</p>