title: How do I validate a first character must begin with A-Z
body: <p>In PHP how do I validate user input like an example below.</p>
  
  <p>Example valid input</p>
  
  <pre><code>$input ='abkc32453';
  $input ='a32453';
  $input ='dsjgjg';
  </code></pre>
  
  <p>Example invalid input</p>
  
  <pre><code>$input ='2sdf23';
  $input ='2121adsasadf';
  $input ='23142134';
  </code></pre>