Substr不允许双位代码在表单上处理

I have an array that uses two codes in a list and pushes them into a form on the next page. Currently I have:

            $code= array();
            $code['c1'] = substr($part, 0, 1);
            $code['c2'] = substr($part, 2);

Now, If I select anything with a single digit c1 and single or double c2 then it adds to the form.

Examples:

1-9
1-15
9-12
9-9

But if I try to add anything with double digits in c1 it doesn't add, like:

10-1
10-2
10-11

If I try

$codes= array();
$codes['c1'] = substr($part, 0, 2);
$codes['c2'] = substr($part, 2);

Then no codes show up.

How can I account for both?

UPDATE:

Currently, the above code, if I select 10-58, will dump c1 as 1 and c2 as -5

You can easily use explode() and list() to split any combination of codes...

$part = "1-15";
$codes = array();
list($codes['c1'], $codes['c2']) = explode("-", $part);
print_r($codes);

gives...

Array
(
    [c1] => 1
    [c2] => 15
)

For

$part = "10-15";

it gives...

Array
(
    [c1] => 10
    [c2] => 15
)

If you are unsure if your data is always correct, you can check that the data has 2 components after using explode() and only convert it then, you can also do something to report and error or whatever you need...

$split = explode("-", $part);
if ( count($split) == 2 ){
    $codes['c1'] = $split[0];
    $codes['c2'] = $split[1];
}
else    {
    // Not of correct format.
}

print_r($codes);