abstract：<!-- <!DOCTYPE html><style> #x{ width: 100px; height: 100px; background-color:red; &n
<!-- <!DOCTYPE html>
<style>
#x{
width: 100px;
height: 100px;
background-color:red;
}
</style>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<div id="x">
</div>
<button onclick="a()">变高</button>
<button onclick="b()">变宽</button>
<button onclick="c()">变色</button>
<button onclick="d()">重置</button>
<button onclick="e()">隐藏</button>
<button onclick="f()">显示</button>
</body>
</html>
<script type="text/javascript">
var x = document.getElementById('x');
function a(){
x.style.height = "200px";
}
function b(){
x.style.width = "200px";
}
function c(){
x.style.backgroundColor = "pink";
}
function d(){
x.style.height = "100px";
x.style.width = "100px";
x.style.backgroundColor = "red";
}
function e(){
x.style.visibility = "hidden";
}
function f(){
x.style.visibility = "visible";
}
</script> -->
<style type="text/css">
.box{width: 120px;height: 250px;border: 1px solid #000;border-radius: 5px;padding: 5px 10px;margin: 20px auto;}
.box div{border-bottom: 1px solid #000;padding-bottom: 10px;margin-bottom: 8px;}
.box input{margin: 8px;}
</style>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<div>
<div>
<input type="checkbox" id="checkall" onclick="checkAll()"><label for="checkall">全选</label>
</div>
<input type="checkbox" name="item[]">选项1<br>
<input type="checkbox" name="item[]">选项2<br>
<input type="checkbox" name="item[]">选项3<br>
<input type="checkbox" name="item[]">选项4<br>
<input type="checkbox" name="item[]">选项5<br>
<input type="checkbox" name="item[]">选项6<br>
</div>
</body>
</html>
<script type="text/javascript">
function checkAll(){
var checkall = document.getElementById('checkall');
var item = document.getElementsByName('item[]');
for(var i = 0;i < item.length ; i++)
{
if(checkall.checked){
item[i].checked = true;
}else{
item[i].checked = false;
}
}
}
</script>
Correcting teacher：天蓬老师Correction time：2019-01-21 17:54:00
Teacher's summary：全选的重点在于复选框的名称, 因为他们是一组元素, 要注意, 还有, 提交作业 用点, 不要这样把代码一复制了事, 应该写上注释, 附上图, 并且将代码放在代码块中高亮提交, 作业可以看出一个人做事的态度, 希望下次看到你的变化