title: PHP check if string contains brackets
body: <p>I just want to build a php function that checking if string is contain brackets and return boolean, anyone can help?</p>
  <p>example:</p>
  <pre><code>$string = &quot;{hallo}&quot;; // true
  $string2 = &quot;h{allo}&quot;; //true
  $string3 = &quot;hal}{o&quot;; //false
  $string4 = &quot;hallo{}&quot;;//false
  </code></pre>