regex return false if string contains at least one questionmark

I have a string where i want to detect if it contains at least one question mark. if it does return false.开发者_StackOverflow I tried to look for it but questiomark seems is a special character. How would you go about it?

thank you.

You just need to escape the ? in your regex. preg_match('/\?/','A string?',$matches) will return a match for ? if one exists.

That said, you could just use strpos() for this. It would be faster since you don't really need a regex engine to find ?

No need for regex.

if (strpos($str, '?') !== false) { 
    return false;
}

// Shorter but always executes due to lack of a conditional structure
// May not be what you need if you're doing various other checks
return strpos($str, '?') === false;

But you're right, ? is a special character in regex. It tells the regex engine to look for zero or one occurrence of something.

If you're involving a check for a question mark in a more complicated regex, then as Paul Kehrer says you simply escape it with a backslash.