source/Core/Language.php
public function getLanguageTag($iLanguage = null)
    {
        if (!isset($iLanguage)) {
            $iLanguage = $this->getBaseLanguage();
        }

        $iLanguage = (int) $iLanguage;

        return ($iLanguage) ? "_$iLanguage" : "";
    }
public function getLanguageTag($iLanguage = null)
    {
        if (!isset($iLanguage)) {
            $iLanguage = $this->getBaseLanguage();
        }

        $iLanguage = (int) $iLanguage;

        return ($iLanguage) ? "_$iLanguage" : "";
    }
public function getLanguageTag ( $ iLanguage = null ) { if ( ! isset ( $ iLanguage ) ) { $ iLanguage = $ this -> getBaseLanguage ( ) ; } $ iLanguage = ( int ) $ iLanguage ; return ( $ iLanguage ) ? "_$iLanguage" : "" ; }
According to user configuration forms and return language prefix.

@param integer $iLanguage User selected language (default null)

@return string
According to user configuration forms and return language prefix .