js请选的！
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script type="text/javascript">
function checkAll(){
var checkall,liem;
checkall=document.getElementById("checkall");
liem=document.getElementsByName("item[]");
for (var i=0;i<liem.length;i++) {
if(checkall.checked){
liem[i].checked=true;
}else{
liem[i].checked=false;
}
}
}
</script>
<h3 >你喜爱的运动</h3>
<input type="checkbox" name="item[]">游泳<br>
<input type="checkbox" name="item[]">跑步<br>
<input type="checkbox" name="item[]">骑马<br>
<input type="checkbox" name="item[]">标枪<br>
<input type="checkbox" id="checkall" onclick="checkAll()"><label for="checkall">全选</label>
</body>
</html>