正则有关问题将图片宽度替换为100%

正则问题 将图片宽度替换为100%
宽度不定的图片https://www.gxlcms.com/
https://www.gxlcms.com/

$str = '


';

https://www.gxlcms.com/
https://www.gxlcms.com/
宽度替换为100%https://www.gxlcms.com/
https://www.gxlcms.com/

$str = '


';

------解决思路----------------------

$str = '


';https://www.gxlcms.com/
https://www.gxlcms.com/
echo preg_replace('/(?<=style="width:).+?px;/i', '100%', $str);

https://www.gxlcms.com/

------解决思路----------------------
这样呢https://www.gxlcms.com/

echo  preg_replace('/(?<=