Policz przedmioty w Div JQuery
$('#element').children('div').length;
Snippets
$('#element').children('div').length;var container_div = document.getElementById('id_of_container_div');
var count = container_div.getElementsByTagName('div').length;
<div class="wrapper">
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
</div>
<script>
alert($('.wrapper').children('.item').length)
</script>