Regex not working as intended with hyphen in a character class [duplicate]

Question

I have this code, but is not working as I expect.

If I write #$% or textwithouterrors the message showed is "correct". So, the regex is not working.

I need to avoid, special characters, spaces and numbers

function validateCity($form) {
    if (preg_match("/[\~!\@#\$\%\^\&*()_+\=-[]{}\\|\'\"\;\:\/\?.>\,\<`]/", $form['city'])) {
        echo ("error");
        return false;
    } else {
        echo("correct");
        return true;
    }
}
validateCity($form);

Answer 1

There are lots of problems - The hypen - should be moved to first or end or escaped otherwise it will be seen as indicating a range. The [] have to be escaped.

Try out what you want in some place like http://gskinner.com/RegExr/

Also you are including lot of stuff in it. Just use something like \w+ as the match for a valid one rather than looking for an invalid one.

Answer 2

Try reversing your logic. Look for the characters you want, not the ones you don't want.