php her kelimenin baş harfi büyük türkçe karakter çözümü

  function strtoupper_tr($deger)
         {
         $deger = str_replace("ç","Ç",$deger);
         $deger = str_replace("ğ","Ğ",$deger);
         $deger = str_replace("ı","I",$deger);
         $deger = str_replace("i","İ",$deger);
         $deger = str_replace("ö","Ö",$deger);
         $deger = str_replace("ü","Ü",$deger);
         $deger = str_replace("ş","Ş",$deger);

         $deger = strtoupper($deger);
         $deger = trim($deger);

         return $deger;
         }

  function strtolower_tr($deger)
         {
         $deger = str_replace("Ç","ç",$deger);
         $deger = str_replace("Ğ","ğ",$deger);
         $deger = str_replace("I","ı",$deger);
         $deger = str_replace("İ","i",$deger);
         $deger = str_replace("Ö","ö",$deger);
         $deger = str_replace("Ü","ü",$deger);
         $deger = str_replace("Ş","ş",$deger);

         $deger = strtolower($deger);
         $deger = trim($deger);

         return $deger;
         }

  function ucwords_tr($deger)
         {
         $deger = explode(" ",trim($deger));
		 $deger2 = $deger[1];
         $deger_tr = "";

         for($x=0; $x < count($deger); $x++)
             {
             $deger_bas = substr($deger[$x],0,1);
             $deger_son = substr($deger[$x],1);
             $deger_bas = strtoupper_tr($deger_bas);

             $deger_tr .= $deger_bas.$deger_son." ";
             }

         $deger_tr = trim($deger_tr);

         return $deger_tr;
         }
$metin = "izmir ürdün çankırı urfa ığdır";

echo mb_convert_case(ucwords_tr(strtolower_tr($metin)), MB_CASE_TITLE, "UTF-8");