我的测试代码全选
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>myall</title>
<style type="text/css">
.mydiv{width:120px;height:250px; border:1px solid green;border-radius: 10px; padding: 5px 10px; margin: 20px auto;}
.mydiv div{border-bottom: 1px solid pink; padding-bottom: 10px; margin-bottom: 8px;}
.mydiv input{margin:10px;}
</style>
<script type="text/javascript">
function checkall(){
var checkall,item;
checkall=document.getElementById("checkall")
item=document.getElementsByName("item[]")
for (var i=0; i<item.length;i++){
if(checkall.checked){
item[i].checked=true;
}else{
item[i].checked=false;
}
}
}
</script>
</head>
<body>
<div>
<div>
<input type="checkbox" id="checkall" onclick="checkall()"><label for="checkall">全选</label>
</div>
<input type="checkbox" name="item[]">选项1<br>
<input type="checkbox" name="item[]">选项2<br>
<input type="checkbox" name="item[]">选项3<br>
<input type="checkbox" name="item[]">选项4<br>
<input type="checkbox" name="item[]">选项5<br>
<input type="checkbox" name="item[]">选项6<br>
</div>
</body>
</html>