title: Add multiple characters to a string at random positions using substr_replace()
body: <p>I want to add &quot;+&quot; character to a string &quot;donalddukeoflagos&quot; multiple times at random positions.</p>
  <p>Donalddukeoflagos will now be don+alddu+ke+ofl+agos</p>
  <p>The code below is working very well, but it can only add one character at a time.</p>
  <pre><code>&lt;?php
  $mailad = &quot;Donalddukeoflagos&quot;;
  $length = (strlen($mailad) - 1);
  $insertposition = rand(1,$length);
  echo substr_replace($mailad,&quot;+&quot;,$insertposition,0);
  ?&gt;
  </code></pre>