Question

I am trying to test a string to see if it contains characters other than alphanumeric or punctuation and, if it does, set an error. I have the code below, but it doesn’t seem to work as it’s letting “CZW205é” pass. I’m hopeless at regex and can’t seem to resolve the problem.

if(!preg_match("/^[a-zA-Z0-9\s\p{P}]/", $product_id)) {
    $errors[$i] = 'Please only enter alpha-numeric characters, dashes, underscores, colons, full-stops, apostrophes, brackets, commas and forward slashes';
    continue;
}

Thanks in advance for your help.

Answer 1

You can do

if(preg_match("/[^a-zA-Z0-9\s\p{P}]/", $product_id)) {
    $errors[$i] = 'Please only enter alpha-numeric characters, dashes, underscores, colons, full-stops, apostrophes, brackets, commas and forward slashes';
    continue;
}

[^...] is a negated character class, it will match as soon as it finds something that is not inside your class.

(And therefor I removed the negation before the preg_match())