$array=array(4,5,1,2,3,1,2,1);
  $ac=array_count_value($array);

            关键字    值

             4     1

           5     1

           1     3

           2     2

           3     1

$arr = array(
      '1011,1003,1008,1001,1000,1004,1012',
      '1009',
      '1011,1003,1111'
    );
$result = array();
foreach ($arr as $str) {
  $str_arr = explode(',', $str);
  foreach ($str_arr as $v) {
    $result[$v] = isset($result[$v]) ? $result[$v] : 0;
    $result[$v] = $result[$v] + 1;
  }
}
print_r($result);