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更新时间：2023-02-21 20:05:09
我认为***的方法是使用 preg_replace_callback.
I think the best approach is to use preg_replace_callback.
此外，我建议使用比目前所建议的更严格的 regexp - 如果您的页面包含一个 <img/> 标记 不包含id属性?
Also I would recommend a slightly more stringent regexp than those suggested so far - what if your page contains an <img /> tag that does not contain an id attribute?
$page = '
<body>
<img src="source.jpg" />
<p>
<img src="source.jpg" id ="hello" alt="nothing" />
<img src="source.jpg" id ="world"/>
</p>
</body>';
function my_callback($matches)
{
static $i = 0;
return $matches[1]."img_".$i++;
}
print preg_replace_callback('/(<img[^>]*ids*=s*")([^"]*)/', "my_callback", $page);
为我产生以下结果:
<body>
<img src="source.jpg" />
<p>
<img src="source.jpg" id ="img_0" alt="nothing" />
<img src="source.jpg" id ="img_1"/>
</p>
</body>
regexp 有两个捕获组，第一个我们保留，第二个我们替换.我使用了很多否定字符类(例如 [^>]* = 直到关闭 >)来确保 <img/> 标签不需要具有 id 属性.
The regexp has two capturing groups, the first we preserve, the second we replace. I've used lots of negative character classes (e.g. [^>]* = up to closing >) to make sure that <img /> tags arn't required to have id attributes.