JS实现无限级网页折叠菜单(类似树形菜单)

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title>无限级折叠菜单JS版title>
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 h3>无限级折叠菜单JavaScript版h3>
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 li>em>em>a href=‘javascript:void(0);‘>菜单_1_1a>
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  li>em>em>a href=‘javascript:void(0);‘>菜单_2_1a>
  ul>
  li>em>em>a href=‘javascript:void(0);‘>菜单_3_1a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
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  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_3_2a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
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  ul>
  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_2_2a>
  ul>
  li>em>em>a href=‘javascript:void(0);‘>菜单_3_1a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
  ul>
  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_3_2a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
  ul>
  li>
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 ul>
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 li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_1_2a>
 ul>
  li>em>em>a href=‘javascript:void(0);‘>菜单_2_1a>
  ul>
  li>em>em>a href=‘javascript:void(0);‘>菜单_3_1a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
  ul>
  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_3_2a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
  ul>
  li>
  ul>
  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_2_2a>
  ul>
  li>em>em>a href=‘javascript:void(0);‘>菜单_3_1a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
  ul>
  li>
  li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_3_2a>
  ul>
   li>em>em>a href=‘javascript:void(0);‘>菜单_4_1a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
   li>
   li id=‘end‘>em>em>a href=‘javascript:void(0);‘>菜单_4_2a>
   ul>
   li>a href=‘javascript:void(0);‘>菜单_5_1a>li>
   li id=‘end‘>a href=‘javascript:void(0);‘>菜单_5_2a>li>
   ul>
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