我自己写的案例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
</style>
<script>
function checkAll() {
let checkall, item;
checkall = document.getElementById("checkall");
item = document.getElementsByName("item[]");
for(let i = 0; i<item.length; i++) {
if(checkall.checked) {
item[i].checked = true;
}else{
item[i].checked = false;
}
}
}
</script>
</head>
<body>
<div class="box">
<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>