مشکل در کلاس مدل

<?php

class Model{
   protected $con;

   public function __construct()
   {
       $this->coect();
   }

   public function coect()
   {
       if (!$this->con) {
           $config = Loader::load('Configs');
           $this->con = new mysqli($config->dbHost, $config->dbUser, $config->dbPass, $config->dbName);
           $this->con->query('SET NAMES 'utf8 '');
           $this->con->set_charset('utf8');
       }
       if ($this->con->coect_ero) {
           exit($this->con->coect_error);
       }
   }

   public function query($query)
   {
       retu $this->con->query($query);
   }

   public function escape($value)
   {
       retu is_null($value) ? 'null' : ''' . $this->con->real_scape_string($value) . "';
   }

   public function insertId()
   {
       retu $this->con->insert_id;
   }

   public function arrayQuery($query)
   {
       $result = [];
       $values = $this->query($query);
       if ($values && $values->num_rows > 0) {
           while ($value = $values->fetch_assoc()) {
               $result[] = $value;
           }
       }
       retu $result;
   }
}

بیشتر ازین خط ارر میده فکر کنم :

retu is_null($value) ? 'null' : '' . $this->con->real_scape_string($value) . '';

$result[] = $value;