title: insert character after first character in string?
body: <pre><code>$var = "Hello";
  </code></pre>
  
  <p>How can I insert the character <strong>:</strong> in after the first character of the string above ? The first character could be anything. So I want to do something like </p>
  
  <pre><code>$res = add("Hello");
  echo $res; // which return H:ello
  </code></pre>
  
  <p>I know how to do this through <code>str_replace</code> but this needs the first character to be always the same.. </p>
  
  <p>Any help would be highly appreciated</p>