emoji 表情编码

 1 $string = 'Lxl?班主任小张老师';
 2 
 3 /**
 4  * emoji 表情编码
 5  *
 6  * @param string $content 内容
 7  * @return string
 8  */
 9 function unicodeEncode(string $content): string
10 {
11     return preg_replace_callback('/./u', function ($matches) {
12         $char = $matches[0];
13         if (strlen($char) > 3) {
14             $unicode = json_encode($char);
15             $unicode = substr($unicode, 1, strlen($unicode) - 2);
16             return preg_replace('/\\\u(\w{4})/', '\\u$1', $unicode);
17         } else {
18             return $char;
19         }
20     }, $content);
21 }
22 
23 $encodedString = unicodeEncode($string);
24 
25 echo $encodedString;