src/View/Helper/DocumentHelper.php
public function lang($isLang = true)
    {
        list($lang, $region) = explode('_', $this->locale);
        return ($isLang) ? Str::low($lang) : Str::low($region);
    }
public function lang($isLang = true)
    {
        list($lang, $region) = explode('_', $this->locale);
        return ($isLang) ? Str::low($lang) : Str::low($region);
    }
public function lang ( $ isLang = true ) { list ( $ lang , $ region ) = explode ( '_' , $ this -> locale ) ; return ( $ isLang ) ? Str :: low ( $ lang ) : Str :: low ( $ region ) ; }
Site language.

@param   bool|true $isLang
@return  string

@throws  \Exception
Site language .