code: public static function getErrorString( int $errno )
      {
          $errno = intval($errno);
          
          $errors = array(
              E_ERROR                => 'E_ERROR',
              E_WARNING              => 'E_WARNING',
              E_PARSE                => 'E_PARSE',
              E_NOTICE               => 'E_NOTICE',
              E_CORE_ERROR           => 'E_CORE_ERROR',
              E_CORE_WARNING         => 'E_CORE_WARNING',
              E_COMPILE_ERROR        => 'E_COMPILE_ERROR',
              E_COMPILE_WARNING      => 'E_COMPILE_WARNING',
              E_USER_ERROR           => 'E_USER_ERROR',
              E_USER_NOTICE          => 'E_USER_NOTICE',
              E_STRICT               => 'E_STRICT',
              E_RECOVERABLE_ERROR    => 'E_RECOVERABLE_ERROR',
          );
          
          $errors[8192] = 'E_DEPRECATED';        // PHP 5.3.0
          $errors[16384] = 'E_USER_DEPRECATED';        // PHP 5.3.0
          
          $errors_desc = array();
          foreach( $errors as $key => $value ){
              if ( ($errno & $key) != 0 ){
                  $errors_desc[] = $value;
              }
          }
          
          return implode( '|', $errors_desc );
      }
docs: Convert PHP error number to string
  
  @param int $errno
  
  @return string