如何使用preg_match_all从字符串中获取单词

Question

我有多个字符串，其中包含HP16SDA305009，HP16JDA305009，HP16SWA305009

我只需要获得SDA，JDA或SWA 我怎么能实现那个

Answer 1

$var = "HP16SDA305009";

 $result = substr($var, 0, -6);

echo $result = substr($result, 4, 3);

Answer 2

$ a ='HP16JDA305009';

        $char = substr($a, 4, -3);

        echo $gen = substr($char, 0, 3);