正则问题 将图片宽度替换为100%

Question

$str = '<p><br></p><img style="width: 513px;" src="
http://xxxx/uploads/details/142163431741415.jpg"><img style="width: 613px;" src="
http://xxxx/uploads/details/14216343172321.jpg"><p><br></p>';echo preg_replace('/(?<=style="width:).+?px;/i', '100%', $str);<p><br></p><img style="width:100%" src="
http://xxxx/uploads/details/142163431741415.jpg"><img style="width:100%" src="
http://xxxx/uploads/details/14216343172321.jpg"><p><br></p>

Answer 1

echo preg_replace('/(?<=<img )style="width\: .+?"/s', 'style="width: 100%;"', $str);

Answer 2

$str = '<p><br></p>
<img style="width: 513px;" src="
http://admin.zhiai/uploads/details/142163431741415.jpg"><p><br></p>
<img src="
http://admin.zhiai/uploads/details/142163713729385.jpg" style="width: 513px;"><p><br></p>
<img src="
http://admin.zhiai/uploads/details/142163714584100.jpg" style="width: 513px;"><p><br></p>
<img src="
http://admin.zhiai/uploads/details/142163715250341.jpg" style="width: 513px;"><p><br></p>';//echo preg_replace('/(?<=style="width:).+?px;/i', '100%', $str);
echo  preg_replace('/(?<=<img )style="width\: .+?"/s', 'style="width: 100%;"', $str);

Answer 3

这样呢
echo  preg_replace('/(?<=<img)(.+?)style="width\: .+?"/s', '$1style="width: 100%;"', $str);