对于复选框的快捷选择-原创手记-慕课网

<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
    <title>无标题文档</title>
</head>

<body>
<form>
    请选择你爱好:<br>
    <input type="checkbox" name="hobby" id="hobby1">  音乐
    <input type="checkbox" name="hobby" id="hobby2">  登山
    <input type="checkbox" name="hobby" id="hobby3">  游泳
    <input type="checkbox" name="hobby" id="hobby4">  阅读
    <input type="checkbox" name="hobby" id="hobby5">  打球
    <input type="checkbox" name="hobby" id="hobby6">  跑步 <br>
    <input type="button" value = "全选" onclick = "checkall();">
    <input type="button" value = "全不选" onclick = "clearall();">
    <p>请输入您要选择爱好的序号，序号为1-6:</p>
    <input id="wb" name="wb" type="text" placeholder="请输入数字1到6">
    <input name="ok" type="button" value="确定" onclick = "checkone();" >
</form>
<script type="text/javascript">
    function checkall(){
        var hobby = document.getElementsByTagName("input");
        // 任务1
        for(var i = 0;i < hobby.length;i++){
            hobby[i].checked = true;
        }
    }
    function clearall(){
        var hobby = document.getElementsByName("hobby");
        // 任务2
        for(var i = 0;i < hobby.length;i++){
            hobby[i].checked = false;
        }
    }

    function checkone(){
        clearall()
        var j = document.getElementById("wb").value;
        // 任务3
        var hobby = document.getElementsByName("hobby");
        if (j >= 1 && j < 7) {
            var hobby = document.getElementById("hobby" + j);
            hobby.checked = true;
        }
        else
            alert("输入数字超出范围！");
        document.getElementById("wb").value=null;
    }

</script>
</body>
</html>