遍历多个checkbox并获取值

<input type="checkbox" name="productTag"  value="1" >
<input type="checkbox" name="productTag"  value="2" >
<input type="checkbox" name="productTag"  value="3" >
<input type="checkbox" name="productTag"  value="4" >

</pre><pre code_snippet_id="1733203" snippet_file_name="blog_20160628_1_8107507" name="code" class="html">var s = $("input[name='productTag']");
s.each(function(i) {
$(this).click(function(){
var tag="";
$(':checkbox[name=productTag]:checked').each(function(){
tag+=$(this).val()+",";

});

if(tag!=""){
$("#tag").val(tag.substring(0,tag.length-1));
}
else{
$("#tag").val("");
}
});
});