PHP - Sanitize字符串删除数字

Question

I am attempting to define allowed characters in an array, and then sanitize strings based on this array. The below code works pretty good except that it removes chars 0-9 too!

Could someone please explain why this is?

Code:

    <?php

//Allowed characters within user data:
$symbols = array();
$symbols += range('a', 'z');
$symbols += range('A', 'Z');
$symbols += range('0', '9');
array_push($symbols,' ','-'); // Allow spaces and hyphens.

//----test 1

//data to test.
$someString = "07mm04dd1776yyyy";

//sanatize
$someString = trim(preg_replace("/[^" . preg_quote(implode('',$symbols), '/') . "]/i", "", $someString));

echo "$someString\n";

//----test 2
$someString = "Another-07/04/1776-test-!@#$%^&*()[]\\;',./\"[]|;\"<>?";

//sanatize
$someString = trim(preg_replace("/[^" . preg_quote(implode('',$symbols), '/') . "]/i", "", $someString));

echo "$someString\n";

?>

Output:

mmddyyyy
Another--test-

Sidenote (edit): This is used in conjunction with a database but it goes beyond the DB, the data in the DB is used to write powershell scripts which import users into Active Directory, and many characters are not allowed, plus the old system only allowed these characters also.

Thank you in advance, Wayne

Answer 1

Going off of what @andrewsi said with the allowed chars not being added to the array, I figured out how to add them properly. The below code shows they are added, and the outputs of the test strings.

There's probably a better way to do this, so I added it to the community wiki.

<?php

//Allowed characters within user data:
$symbols = array();
array_push($symbols,implode("",range('0', '9')));
array_push($symbols,implode("",range('a', 'z')));
array_push($symbols,implode("",range('A', 'Z')));
array_push($symbols,' ','-'); // Allow spaces and hyphens.

print_r($symbols);
echo "\n";

//----test 1

//data to test.
$someString = "07mm04dd1776yyyy";

//sanatize
$someString = trim(preg_replace("/[^" . preg_quote(implode('',$symbols), '/') . "]/", "", $someString));

echo "$someString\n";

//----test 2
$someString = "Another-07/04/1776-test-!@#$%^&*()[]\\;',./\"[]|;\"<>?";

//sanatize
$someString = trim(preg_replace("/[^" . preg_quote(implode('',$symbols), '/') . "]/", "", $someString));

echo "$someString\n";

?>

Output:

Array
(
    [0] => 0123456789
    [1] => abcdefghijklmnopqrstuvwxyz
    [2] => ABCDEFGHIJKLMNOPQRSTUVWXYZ
    [3] =>  
    [4] => -
)

07mm04dd1776yyyy
Another-07041776-test-