PHP的preg_match返回两个字符串

Question

之间的串

我怎样才能得到这个链接 “http://example.com/view.php?id=5841” 从代码：

<h3 class="coursename"><a class="" href="http://example.com/view.php?id=521">D<span class="highlight">LAW</span> <span class="highlight">130</span>Management</a></h3><div class="moreinfo"></div></div><div class="content"><ul class="teachers"><li>Teacher: <a href="http://example.com/">John</a></li></ul><div class="coursecat">Category: <a class="" href="http://example.com/">First</a></div></div></div><div class="coursebox clearfix even" data-courseid="5841" data-type="1"><div class="info"><h3 class="coursename"><a class="" href="http://example.com/view.php?id=5841"><span class="highlight">LAW</span> <span class="highlight">130` 

我想：

preg_match('/href="(.*)"><span class="highlight">LAW/isU',$BBB,$AAA); 

，结果是：

http://example.com/view.php?id=521">D<span class="highlight">LAW</span> <span class="highlight">130</span>Management</a></h3><div class="moreinfo"></div></div><div class="content"><ul class="teachers"><li>Teacher: <a href="http://example.com/">John</a></li></ul><div class="coursecat">Category: <a class="" href="http://example.com/">First</a></div></div></div><div class="coursebox clearfix even" data-courseid="5841" data-type="1"><div class="info"><h3 class="coursename"><a class="" href="http://example.com/view.php?id=5841 

Answer 1

用此代替：

/href="(.[^<]*?)"><span class="highlight">LAW/isU 

这是一种告诉正则表达式找到与你想要的最短表达式相匹配的简单方法。

Answer 2

使用XPath查询：

libxml_use_internal_errors(true); 
$dom = new DOMDocument; 
$dom->loadHTML($yourHTML); 

$xp = new DOMXPath($dom); 
$link = $xp->query('//a[span[@class="highlight"]][starts-with(.,"LAW")][1]/@href')->item(0)->nodeValue; 

echo $link; 

查询详情：

// # axe: anywhere in the DOM tree 
a # axe: a "a" tag 
[span[@class="highlight"]] # predicate: the "a" tag has for direct child a "span" tag 
          # with a "class" attribute equal to "highlight" 
[starts-with(.,"LAW")]  # predicate: its text content begins with "LAW" 
[1]      # predicate: first occurrence (no need to search another one) 
/@href      # axe: its "href" attribute