Conversione stringa in array

[Santino83_02]

$stringhe = array("1-4;",
"1-2;",
"2-4;");

$arr = array();

foreach($stringhe as $stringa){

$vet1=explode(";",$stringa); 
$vet2=explode("-",$vet1[0]); 

if(!array_key_exists($vet2[0],$arr)){
   $arr[$vet2[0]] = $vet2[1];
}else{
   if(!is_array($arr[$vet2[0]])){
      
       $arr[$vet2[0]] = array($arr[$vet2[0]],$vet2[1]);

   }else{

       $arr[$vet2[0]][] = $vet2[1];
   }
}

}