PHP 判斷字符串是否符合指定格式編碼－mb_check_encoding

純數字和英文字母組合：

$utf8Str = "I have 4 books and 2 magazines to check out. ";

var_dump(mb_check_encoding($utf8Str,'utf-8')); //輸出true
var_dump(mb_check_encoding($utf8Str,'gbk')); //輸出true

gbk編碼的字符串

$str = '迷你tablet或於本月23日發佈。';

var_dump(mb_check_encoding($str,'utf-8'));  //輸出false
var_dump(mb_check_encoding($str,'gbk')); //輸出true

utf-8編碼的字符串

$str = '迷你tablet或於本月23日發佈。';

var_dump(mb_check_encoding($str,'utf-8'));  //輸出true
var_dump(mb_check_encoding($str,'gbk')); //輸出false