How to implement exception handling class in PHP

<?php
header(&#39;content-type:text/html;charset=UTF-8&#39;);
// 创建email异常处理类
class emailException extends exception
{
}
// 创建pwd异常处理类
class pwdException extends exception
{
  public function __tostring(){
    return $this->getMessage().&#39;in file:&#39;.$this->getFile().&#39;on line:&#39;.$this->getLine();
  }
}
function reg($reginfo = null)
{
  // 依据不同错误抛出不同异常
  if (empty($reginfo) || !isset($reginfo)) {
    throw new Exception(&#39;参数非法&#39;);
  }
  if (empty($reginfo[&#39;email&#39;])) {
    throw new emailException(&#39;邮件为空&#39;);
  }
  if ($reginfo[&#39;pwd&#39;] != $reginfo[&#39;repwd&#39;]) {
    throw new pwdException(&#39;两次密码不一致！&#39;);
  }
}
// 接收不同异常，并针对性处理！
try {
  reg(array(&#39;email&#39; => &#39;1078789950@qq.com&#39;, &#39;pwd&#39; => &#39;123&#39;, &#39;repwd&#39; => &#39;1231&#39; ));
} catch (Exception $e) {
  echo $e ->getMessage();
} catch (emailException $ee) {
  echo $ee ->getMessage();
} catch (pwdException $ep) {
  echo $ep;
}