PHP function example to determine whether string encoding is utf8

/**
* Determine string encoding
* edit by bbs.it-home.org
*/
function is_utf8($word)
{
 if(preg_match("/^([".chr(228)."-".chr( 233)."]developed[".chr(128)."-".chr(191)."]developed[".chr(128)."-".chr(191)."]developed)developed/" ,$word) == true || preg_match("/([".chr(228)."-".chr(233)."]developed[".chr(128)."-".chr(191) ."]developed[".chr(128)."-".chr(191)."]developed)developed$/",$word) == true || preg_match("/([".chr(228) ."-".chr(233)."]Developed[".chr(128)."-".chr(191)."]Developed[".chr(128)."-".chr(191). "]Developed){2,}/",$word) == true) {
 return true;
 }else {
 return false;
 }
}
$t = 'wangbin';
//$t = iconv ('GB2312','UTF-8',$t)
var_dump(is_utf8($t));
?>

In addition, the function mb_detect_encoding in PHP can also implement such a function .

Detect whether the string is utf8 encoded code under PHP, function: mb_detect_encoding, this requires the mb_string library to be installed in the PHP environment. For related information about the mb_detect_encoding function, you can refer to: php function mb_detect_encoding to obtain string encoding php mb_detect_encoding detects the problem of incorrect string encoding The implemented function is as follows:

/**
* Check whether it is utf8 encoding
* edit by bbs.it-home.org
*/
 function is_utf8($string) {
 return preg_match('%^(?:
 [x09x0Ax0Dx20-x7E] # ASCII
 | [xC2-xDF][x80-xBF] # non-overlong 2-byte
 | xE0[xA0-xBF][x80-xBF] # excluding overlongs
 | [xE1-xECxEExEF][x80-xBF]{2} # straight 3-byte
 | xED[x80-x9F][x80-xBF] # excluding surrogates
 | x80-xBF]{3} # planes 4-15
 | xF4[x80-x8F][x80-xBF]{2} # plane 16
 )*$%xs', $string);
}
?>

Instructions: The accuracy is basically the same as mb_detect_encoding, right or wrong. But it is basically enough for daily development. I hope everyone likes it.