<script>
var count= 0;
var objs = document.getElementsByTagName('input');
for (var i= 0; i<objs.length; i++){
if (objs[i].getAttribute("type") == "checkbox")
count +=1;
}
window.alert(count);
</script>
var count= 0;
var objs = document.getElementsByTagName('input');
for (var i= 0; i<objs.length; i++){
if (objs[i].getAttribute("type") == "checkbox")
count +=1;
}
window.alert(count);
</script>
这段代码必须放在checkbox控件代码后面,否则无法得知控件数目,为0.