in_array function, why this doesn't work? - php

Question

I'm trying to validate a string to an array of numbers. If the string only contains numbers then the function should validate, but in_array isn't working, any suggestions?
$list = array(0,1,2,3,4,5,6,7,8,9);
$word = 'word';
$split = str_split($word);
foreach ($split as $s) {
if (!in_array($s, $list)) {
print 'asdf';
}
}
here is the class:
class Validate_Rule_Whitelist {
public function validate($data, $whitelist) {
if (!Validate_Rule_Type_Character::getInstance()->validate($data)) {
return false;
}
$invalids = array();
$data_array = str_split($data);
foreach ($data_array as $k => $char) {
if (!in_array($char, $whitelist)) {
$invalids[] = 'Invalid character at position '.$k.'.';
}
}
if (!empty($invalids)) {
$message = implode(' ', $invalids);
return $message;
}
return true;
}
}

Answer 1

in_array comparison with loosely typed values is somewhat strange. What would work in your case is:
$list = array('0','1','2','3','4','5','6','7','8','9');
$word = 'word';
$split = str_split($word);
foreach ($split as $s) {
if (!in_array($s, $list, true)) {
print 'asdf';
}
}
This compares strings with strings and results in no surprises.
But, as noted in the comments already, this is quite wrong way to do things and it is much better to use filter_var() or regular expressions** to achieve what you're trying.

Answer 2

it's ugly as sin but it works, no elegant solution here, just a double loop, if you see any problems please let me know
$match = array();
foreach ($data_array as $k => $char) {
foreach ($whitelist as $w) {
if (!isset($match[$k])) {
if ($char === $w) {
$match[$k] = true;
}
}
}
if (!isset($match[$k]) || $match[$k] !== true) {
$invalids[$k] = 'Invalid character at position '.$k.'.';
}
}

Answer 3

Something along the lines of this should work:
<?php
$validate_me = '123xyz';
if(preg_match("/[^0-9]/", $validate_me, $matches))
print "non-digit detected";
?>

Answer 4

update: add the $type = gettype ... settype($char, $type) to allow === to function correctly when checking for integers
foreach ($data_array as $k => $char) {
foreach ($whitelist as $w) {
if (!isset($match[$k])) {
$type = gettype($w);
if (gettype($char) !== $type) {
settype($char, $type);
}
if ($char === $w) {
$match[$k] = true;
}
}
}
...