PHP preg_match 仅特殊字符

Question

I try to find a preg_match that filters strings that contain only special characters like - .

However, the string itself can contain special characters but it should not be special characters only.

Any ideas how to do that?

Result should return true if string only contains special characters. So something like

if(preg_match('//',$string)) echo $string; //I leave the pattern empty as this is the actual question.

Answer 1

You need to match the string for any alphanumeric character.

$one=  "%^&";
$two = "asd%asd";


function notOnlySpecialChars($str) {
    if (preg_match('/[A-Za-z0-9]/', $str)) { //Replaced _ with -
        return true;
    } else {
        return false;
    }
}
notOnlySpecialChars($one); //false
notOnlySpecialChars($two); //true