<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<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" >
<input name="ok" type="button" value="确定" onclick = "checkone();">
</form>
<script type="text/javascript">
function checkall(){
var hobby = document.getElementsByTagName("input");
// var btns = document.getElementsByName("hobby");
// for(var i=0;i<btns.length;i++)
// {
// btns[i].checked = true;
// }
for(var i=0;i<hobby.length;i++)
{
if(hobby[i].type == "checkbox")
{
hobby[i].checked=true;
}
}
// 任务1
}
function clearall(){
var hobby = document.getElementsByName("hobby");
for(var i=0;i<hobby.length;i++)
{
hobby[i].checked = false;
}
// 任务2
}
function checkone(){
var j=document.getElementById("wb").value;
var hobby = document.getElementsByName("hobby");
var js = j.split(",");
for(var i=0;i<js.length;i++)
{
var num = js[i]-1;
hobby[num].checked = true;
}
// 任务3
}
</script>
</body>
</html>
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<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" >
<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 - 1; i++) {
if (hobby[i]['name'] == 'hobby') {
hobby[i].checked = true;
}
}
}
function clearall(){
var hobby = document.getElementsByName("hobby");
// 任务2
for (var i = 0; i <= hobby.length - 1; i++) {
hobby[i].checked = false;
}
}
function checkone(){
var j=document.getElementById("wb").value;
// 任务3
document.getElementById("hobby"+j).checked = true;
}
</script>
</body>
</html>
任务三我的是这样的，正常运行：
function checkone(){
var j=document.getElementById("wb").value;
var inpu=document.getElementsByTagName("input");
// 任务3
for(var n=0;n<inpu.length;n++){
if(j==(n+1)){
inpu[n].checked=true;
}else{
}
}
}
第三个我就加了个它-------document.getElementById("hobby"+j).checked = true;