我也发一个
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>id-name-tag的用途</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">
<input name="ok" type="button" value="确定" onclick="checkone();">
</form>
<script type="text/javascript">
function checkall() {
var hobby = document.getElementsByTagName("input");
for (var i = 0; i < hobby.length; i++) {
if (hobby[i].type == "checkbox") {
hobby[i].checked = true;
// console.log(i + hobby[i].checked);
}
}
// 任务1
}
function clearall() {
var hobby = document.getElementsByName("hobby");
for (var i = 0; i < hobby.length; i++) {
hobby[i].checked = false
// console.log(i + hobby[i].checked);
}
// 任务2
}
function checkone() {
var j = document.getElementById("wb").value;
if (j != Math.floor(j)) {
alert("请输入正确的值：1-6");
} else if (j < 0 || j > 6) {
alert("请输入正确的值：1-6");
} else {
console.log(document.getElementById("hobby" + j).checked);
document.getElementById("hobby" + j).checked = true;
}
// 任务3
}
</script>
</body>
</html>
