How do I detect non-ASCII characters in a string?

Question

If I have a PHP string, how can I determine if it contains at least one non-ASCII character or not, in an efficient way? And by non-ASCII character, I mean any character tha

Answer 1

Try: (Source)

function is_ascii( $string = '' ) {
    return ( bool ) ! preg_match( '/[\\x80-\\xff]+/' , $string );
}

Although, all of the above answers are correct, but depending upon the input, these solutions may give wrong answers. See the last section in this ASCII validation post.