<script>
var keleyijson={"plug1":"myslider","plug2":"zonemenu","plug3":"keleyi"}

function JSONLength(obj) {
var size = 0, key;
for (key in obj) {
if (obj.hasOwnProperty(key)) size++;
}
return size;
};

document.write("json对象的元素个数是："+JSONLength(keleyijson));
</script>

获取json的元素数量的代码