Question

I’m working on a PHP script that updates some tracking numbers based on an uploaded CSV file. The import worked fine for some time, then the exports started having quotation marks around the values. I thought this would be fine, but it started rejecting the files. Doing some debugging and var_dumps, I discovered a very strange situation I have never seen before – An associative array with two indices with the same name. I ran the code setting the fields (shown below) and added a line:

$v['order_id'] = '119205';

After running that line, the var_dump was as follows:

array(15) {
  ["order_id"]=>
  string(6) "119205"
  ["Tracking Number"]=>
  string(22) "6735675476254654756"
  ["Postage"]=>
  string(4) "1.64"
  ["order_id"]=>
  string(6) "119205"
}

Some fields removed for brevity. As you can see, there are two ["order_id"] indices. How is this even possible?

Here is the code that sets the values of the array dumped above:

$v = array();
    foreach ($map as $k => $n) {
    $v[$n] = @$data[$k];
}

with $map being the CSV header row. Trying to reference $v['order_id'] without running the $v['order_id'] = '119205'; line resulted in this error:

Notice:  Undefined index: order_id in /dir/to/php/file/php_file.php</b> on line 29

Manually setting the index worked as expected, pulling the rest of the data from $v without issue.

EDIT:

Dumping the array_keys resulted in:

[0]=>
string(11) "order_id"

and:

[14]=>
string(8) "order_id"

making the first one three characters longer.

var_export still resulted in identical indices.

How can I get rid of these invisible characters? I’ve already tried $v[trim($n)] = @$data[$k]; in the foreach().

Answer 1

Try var_dump(array_keys($v)). Find the key that looks like order_id and make sure the string’s length is exactly 8. I suspect there may be a NUL character in there, which would give it a length of 9 and cause it to not respond to order_id.