W3Schools 在线编辑工具（TIY） V3.0
编辑的代码:
运行代码 »
©
w3s.com.cn
<!DOCTYPE html> <html> <head> <script type="text/javascript" src="/jquery/jquery.js"></script> </head> <body> <ul> <li><strong>list</strong> item 1 - one strong tag</li> <li><strong>list</strong> item <strong>2</strong> - two <span>strong tags</span></li> <li>list item 3</li> <li>list item 4</li> <li>list item 5</li> </ul> <script> $("li").click(function() { var $li = $(this), isWithTwo = $li.is(function() { return $('strong', this).length === 2; }); if ( isWithTwo ) { $li.css("background-color", "green"); } else { $li.css("background-color", "red"); } }); </script> </body> </html>