全选和反选 

<!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>
</head>

<body>
    <input type="checkbox" class="checkall">
    <br>
    <input type="checkbox" class="checkone">
    <input type="checkbox" class="checkone">
    <input type="checkbox" class="checkone">

    <script>
        var all = document.querySelector('.checkall')
        var one = document.querySelectorAll('.checkone')
        console.log(one)
        all.onclick = function () {
            for (var i = 0; i < one.length; i++) {
                one[i].checked = all.checked
            }
        }

        for (var i = 0; i < one.length; i++) {
            one[i].onclick = function () {
                for (var j = 0; j < one.length; j++) {
                    if (!one[j].checked) {
                        break
                    }
                }
                all.checked = j === one.length ? true : false
            }
        }







    </script>
</body>

</html>

 

posted @ 2021-07-07 18:44  JSkolo_yyds  阅读(53)  评论(0)    收藏  举报