<script type="text/javascript">
var txt = '{"http://habrahabr.ru/events/coming/":{"id": "http://habrahabr.ru/events/coming/","shares": 832},"http://habrahabr.ru/":{"id": "http://habrahabr.ru/","shares": 11}}';
re = /"shares": [0-9]+[^0-9]/gm;
found = txt.match(re);
for(var i in found){
found[i]=found[i].replace(/^[^0-9]+/g,'')
found[i]=parseFloat(found[i])
alert('>'+found[i]+'<')
}
</script>