用jquery统计子菜单的条数(demo)

<!doctype html>

<head>

/* Remove margin padding */

body,h1,h2,h3,h4,h5,h6,hr,p,blockquote,dl,dt,dd,ul,ol,li,pre,form,fieldset,legend,button,input,textarea,th,td { margin:0; padding:0; }

/* Default Font */

body,button,input,select,textarea { font:12px/1.5 \5b8b\4f53,arial,sans-serif; }

h1,h2,h3,h4,h5,h6 { font-size:100%; }

address,cite,dfn,em,var { font-style:normal; }

code,kbd,pre,samp { font-family:courier new,courier,monospace; }

small { font-size:12px; }

ul,ol { list-style:none; }

a { text-decoration:none; }

a:hover { text-decoration:underline; }

sup { vertical-align:text-top; }

sub { vertical-align:text-bottom; }

legend { color:#000; }

fieldset,img { border:0; }

button,input,select,textarea{ font-size:100%; }

table { border-collapse:collapse; border-spacing:0; }

.col-main{ float:left; width:100%; min-height:1px; }

.col-sub,.col-extra { float:left; }

.layout:after,.main-wrap:after,.col-sub:after,.col-extra:after { content:'\20'; display:block; height:0; clear:both; }

.layout,.main-wrap,.col-sub,.col-extra { zoom:1; }

/* Common Features */

.hidden { display:none; }

.invisible { visibility:hidden; }

/* Remove Float */

.clear { display:block; height:0; overflow:hidden; clear:both; }

.clearfix:after { content:'\20'; display:block; height:0; clear:both; }

.clearfix { *zoom:1; }

/* For non ie browsers also display the vertical scroll bar by default, to prevent the flicker caused by the scroll bar */

html { overflow-y:scroll; }

/* Default link styles */

a:link {color: #003399; }

a:visited {color: #123689;}

a:hover {color: #FF6600;}

</style>

</head>

<body>

.menu { width:200px; border:1px solid #CCC; margin-bottom:20px }

.menu h3 { height:30px; line-height:30px; background:#ccc; }

.menu .num { font-weight:bold; color:red; padding-left:30px; }

</style>

<ul>

</ul>

</div>

<ul>

</ul>

</div>

<ul>

</ul>

</div>

for ( var i=0; i<$('.menu').length; i++){

var num = $('.menu').eq(i).children('ul').children('li').length;

$('.menu').eq(i).find('.num').text(num);

}

</script>

</body>

</html>

补充：web前端 , JavaScript ,