Separate elements of a vector according to its type

I need to separate the elements of a array according to whether it is number , text and alphanumeric but the alphanumerics are not printed: (

<?php
$d[0] = 13;
$d[1] = 133;
$d[2] = 45;
$d[3] = "Hice 89 lagartijas";
$d[4] = 778;
$d[5] = 67;
$d[6] = "Que onda";
$d[7] = 456;
$d[8] = 34;
$d[9] = 645;

$indiceNumeros = 0;
$indiceLetras = 0;
$indiceAlfaNumericos = 0;
for($i=0; $i<=9; $i++){
  switch($d){
      case is_numeric($d[$i]):            
          $s[$indiceNumeros] = $d[$i];
          $indiceNumeros++;
          break;
      case is_string($d[$i]):
          $k[$indiceLetras] = $d[$i];
          $indiceLetras++;
          break;
       case ctype_alpha($d[$i]):
           $a[$indiceAlfaNumericos] = $d[$i];
           $indiceAlfaNumericos++;
           break;
       
  }
}
echo "Numeros <BR>";

for($i = 0; $i<count($s); $i++){
  echo "$s[$i] <br>";
}
echo "<br> Textos <BR>";

for($i = 0; $i<count($k); $i++){
  echo "$k[$i] <br>";
}
echo "<br> Alfanuméricos <BR>";
for($i = 0; $i<count($a); $i++){
  echo "$a[$i] <br>";
}