模型Codeigniter中的非法字符串偏移

Question

请帮助我遇到麻烦，我有模型和错误，请帮助我

 public function website_footer() {
   $data = '';
    $settings = $this->check_settings_exist(13);
    if ($settings != false) {
        $setting_details = $this->objectToArray(json_decode('[' . $settings . ']'));
        $i = 1;
        foreach ($setting_details[0] as $key => $value) {
            if ($i == count($setting_details[0])) {
                $data[$key] = $value;
            } else {
               $data[$key   ] = $value;
            }
            ++$i;
        }
        return $data;
    } else {
        return '';
    }
}

错误：

  

遇到PHP错误

     

严重性：警告

     

消息：非法字符串偏移量'website_footer'

     

文件名：models / Write_setting_model.php

     

行号：97