nth-child(Xn+Y) selector
nth-child(Xn+Y) selector
by Mingtao Sun
HTML
<ul id='ul1'>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
</ul>
<div id ='log'></div>
JavaScript
$(function() {
var onlyChild = $('ul :nth-child(3n+1)');
onlyChild.each(function(){
$('#log').append($(this).text()+ ' ');
});
});