<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>全选</title>
<style>
ul {
list-style: none;
}
</style>
</head>
<body>
<ul>
<li>全选<input type='checkbox' id='all'></li>
<li>Java<input type='checkbox' class='item'></li>
<li>javaScript<input type='checkbox' class='item'></li>
<li>C++<input type='checkbox' class='item'></li>
<li>python<input type='checkbox' class='item'></li>
<li>.net<input type='checkbox' class='item'></li>
</ul>
<script>
let all = document.getElementById("all")
let items = Array.from(document.getElementsByClassName("item"))
all.onchange = ()=>{
items.forEach(item=>{
item.checked = all.checked
})
}
items.forEach(item=>{
item.onchange = ()=>{
all.checked = items.every(item=>item.checked)
}
})
</script>
</body>
</html>
