求一例PHP正则表达式的写法

语言是PHP

http://www.digitaling.com/projects/13423.html
http://baidu.com
http://www.yeelight.com/zh_CN/product/yeelight-sunflower

以上几种情况中希望能得到如下结果：

www.digitaling.com
baidu.com
www.yeelight.com

---

为何要用正则=_=?! DEMO:http://3v4l.org/lmADo

<?php
$tests = array(
    "http://www.digitaling.com/projects/13423.html",
    "http://baidu.com",
    "http://www.yeelight.com/zh_CN/product/yeelight-sunflower"
);

foreach($tests as $test) {
    echo parse_url($test, PHP_URL_HOST), "\r\n";
}

---

php
<?php

$str = "
http://www.digitaling.com/projects/13423.html
http://baidu.com
http://www.yeelight.com/zh_CN/product/yeelight-sunflower
";

$preg = "/http:\/\/([a-zA-Z0-9.]*)/";
preg_match_all($preg, $str, $arr);

var_dump($arr[1]);

最终结果：

phparray(3) { [0]=> string(18) "www.digitaling.com" [1]=> string(9) "baidu.com" [2]=> string(16) "www.yeelight.com" }

看看是不是你需要的。另外，你说的这三种情况是同在一个字符串里面呢？还是说，这三种情况随机只出现一个？