Question

我正在尝试在菜单上执行preg_match。但是php似乎一直在跳过第一场比赛。我找不到原因。

<div id="subnav">
<div class="wrap">
<ul id="menu-patternstutorials" class="nav superfish">
  <li id="menu-item-11512" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home current-menu-ancestor menu-item-11512">
    <a href="http://localhost/Sites/craftpassion/">Patterns Tutorials</a> 
    <ul class="sub-menu"> 
  <li id="menu-item-11506" class="menu-item menu-item-type-taxonomy menu-item-object-category current-menu-ancestor current-menu-parent menu-item-11506 star-li-bg">
      <a title=" TEST" href="http://localhost/Sites/craftpassion/category/needle-craft/sewing">Sewing</a> 
  <ul class="sub-menu"> 
    <li id="menu-item-11508" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home current-menu-ancestor current-menu-parent menu-item-11508">
        <a href="http://localhost/Sites/craftpassion/">Basic Techniques</a> 
    <ul class="sub-menu">

PHP

    $pattern = '#<ul[^`]*?>[\s]*?<li [^`]*?>[\s]*?<a[^`]*?>([^`]*?)</a>[\s]*?<ul[^`]*?>#i';
    preg_match($pattern, $menu, $matches);

我在期待：

<ul id="menu-patternstutorials" class="nav superfish">
  <li id="menu-item-11512" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home current-menu-ancestor menu-item-11512">
    <a href="http://localhost/Sites/craftpassion/">Patterns Tutorials</a> 
    <ul class="sub-menu">

但继续得到：

<ul class="sub-menu"> 
  <li id="menu-item-11506" class="menu-item menu-item-type-taxonomy menu-item-object-category current-menu-ancestor current-menu-parent menu-item-11506 star-li-bg">
      <a title=" TEST" href="http://localhost/Sites/craftpassion/category/needle-craft/sewing">Sewing</a> 
  <ul class="sub-menu">

为什么它不匹配第一个预期的？

Answer 1

HTML！=常规语言。参见：

RegEx match open tags except XHTML self-contained tags

Answer 2

不要使用正则表达式解析（X）HTML。由于您没有处理常规语言（这是常规表达式能够处理的语言），因此无法（正确地）执行此操作。请改用DOM或SAX解析器。

正则表达式首先应该保持跳过匹配

2 个答案: