JavaScript全选和反选
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
#box{
border-radius: 5px;
height: 260px;
width: 200px;
background: #ccc;
margin: 0 auto;
}
input{
margin-top: 10px;
}
span{
text-align: center;
}
</style>
<script type="text/javascript">
function checkall(){
var checkall,item;
checkall = document.getElementById('checkall')
item = document.getElementsByName('item[]')
for(var i =0;i<item.length;i++){
if(checkall.checked){
item[i].checked = true;
}else{
item[i].checked = false;
}
}
}
function checkothers(){
var checkothers,item;
checkothers = document.getElementById('checkothers')
item = document.getElementsByName('item[]')
for(var i =0;i<item.length;i++){
if(checkothers.checked){
if(item[i].checked){
item[i].checked = false;
}else{
item[i].checked = true;
}
}
}
}
</script>
</head>
<body>
<div id="box">
<span><h1>选择你的爱好</h1></span>
<input type="checkbox" id="checkall"onclick="checkall()"><label for="checkall">全选</label>
<input type="checkbox" id="checkothers"onclick="checkothers()"><label for="checkothers">反选</label><br>
<hr>
<input type="checkbox" name="item[]">吃饭<br>
<input type="checkbox" name="item[]">睡觉<br>
<input type="checkbox" name="item[]">看小说<br>
<input type="checkbox" name="item[]">玩游戏<br>
<input type="checkbox" name="item[]">旅游<br>
</div>
</body>
</html>
总结：document.getElementById中 Element不加s，document.getElementsByName和getElementsByClassName 需要加s