in_array函数，为什么这不起作用？

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

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 3

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 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;
            }
        }
    }
...