Difference between declaring methods in php 5.3 and 5.6 -

i working on codebase runs on live environment php version 5.3.29.

i've tried moving on test environment uses php version 5.6.28.

i noticed loadconfig method doesn't invoked if declare private keyword.

is breaking change between version 5.3 , 5.6 methods need declared with, private, public, protected etc?

this partial example class:

class baseconfig  {     var $dao = null;     var $appconfig = array();     var $frameworkbootstrap = null;     var $reserved = array(cmd_param, 'go', 'submit', 'xsubmit');      function baseconfig() {         register_shutdown_function(array(&$this, '_doshutdown'));          $this->frameworkbootstrap = parse_ini_file(dirname(__file__) . '/' . framework_bootstrap_config);         $this->loadconfig();     }       function loadconfig() {         require_once(dirname(__file__) . '/configdao.class.php');          $dao = new configdao();         $this->appconfig = $dao->getallsettings();     } }

these errors displayed:

strict standards: declaration of simpleconfig::getinstance() should compatible & baseconfig::getinstance($type = null)

strict standards: non-static method simpleconfig::getinstance() should not called statically

strict standards: non-static method baseconfig::getinstance() should not called statically

notice: use of undefined constant cmd_param - assumed 'cmd_param'

warning: parse_ini_file(www/conf/config.app.settings.ini.php): failed open stream: no such file or directory

notice: constant admin_save_quantity_shipping_cmd defined

strict standards: non-static method util::getself() should not called statically

strict standards: non-static method util::cleanuri() should not called statically

strict standards: non-static method util::getprotocol() should not called statically

notice: undefined index: https

notice: undefined index: script_uri

notice: undefined index: http_x_forwarded_host

strict standards: non-static method request::getinstance()

strict standards: declaration of mysqlqueryresult::getrow() should compatible queryresult::getrow($index, $type)

strict standards: declaration of mysqldatabase::getinstance() should compatible database::getinstance()

deprecated: non-static method util::sanitize() should not called statically, assuming $this incompatible context

deprecated: non-static method util::checkarray() should not called statically, assuming $this incompatible context

notice: variable references should returned reference

strict standards: non-static method language::getinstance() should not called statically

deprecated: non-static method bootstrapconfig::getinstance() should not called statically, assuming $this incompatible context

deprecated: non-static method baseconfig::getinstance() should not called statically, assuming $this incompatible context

warning: parse_ini_file(/var/www/conf/config.app.bootstrap.ini.php): failed open stream: no such file or directory

deprecated: non-static method mysqldatabase::getinstance() should not called statically, assuming $this incompatible context

deprecated: mysql_connect(): mysql extension deprecated , removed in future: use mysqli or pdo instead

deprecated: non-static method util::mysql_real_escape_string() should not called statically, assuming $this incompatible context

deprecated: non-static method session::getinstance() should not called statically, assuming $this incompatible context

notice: variable references should returned reference

deprecated: non-static method bootstrapconfig::getinstance() should not called statically, assuming $this incompatible context

deprecated: non-static method baseconfig::getinstance() should not called statically, assuming $this incompatible context

deprecated: non-static method mysqldatabase::getinstance() should not called statically, assuming $this incompatible context

deprecated: mysql_connect(): mysql extension deprecated , removed in future: use mysqli or pdo instead

deprecated: non-static method bootstrapconfig::getinstance() should not called statically, assuming $this incompatible context

deprecated: non-static method baseconfig::getinstance() should not called statically, assuming $this incompatible context

deprecated: non-static method util::mysql_real_escape_string() should not called statically, assuming $this incompatible context

deprecated: non-static method beanmapper::populatebean() should not called statically, assuming $this incompatible context

strict standards: declaration of productitem::getweightamount() should compatible item::getweightamount($mult = true)

strict standards: declaration of productitem::getselectedoption() should compatible & item::getselectedoption()

notice: undefined index: digishopcachedisabled

deprecated: non-static method util::santizeinput() should not called statically, assuming $this incompatible context

notice: variable references should returned reference

notice: undefined index: xdigishopadminsale

deprecated: non-static method util::santizeinput() should not called statically, assuming $this incompatible context

notice: variable references should returned reference

notice: constant cache_disabled defined