将一段html中的所有<div>
替换成这样
<div1>
<div2>
<div3>
...
<divn>
------解决方案--------------------
$html = "<div>abc,abc,abc,<span>abc</span>,......</div>";
echo preg_replace('/abc/e','++$i',$html);
------解决方案--------------------
$str = '<div>abc,abc,abc</div><span>abc</span>';
$i=1;
$newstr = preg_replace_callback('
------解决方案--------------------
abc
------解决方案--------------------
', function($match) use(&$i){return $i++;}, $str);
echo $newstr;