checkbox 点击全选

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<div>
    <label><input type="checkbox" name="aAll">全选</label><br>
    <label><input type="checkbox" name="a">A</label><br>
    <label><input type="checkbox" name="a">B</label><br>
    <label><input type="checkbox" name="a">C</label>
</div>
<script type="text/javascript">
    var all = document.getElementsByName("aAll")[0];
    var aCheck = document.getElementsByName("a");
    all.onclick = function(){
        if(this.checked){
            for(var i of aCheck){
                i.checked = true;
            }
        }else{
            for(var i of aCheck){
                i.checked = false;
            }
        }
    }
    for(var i of aCheck){
        i.onclick = function(){
            if(!this.checked){
                all.checked = false;
            }
        }
    }
</script>
</body>
</html>
原文地址:https://www.cnblogs.com/ahu666/p/6140231.html