<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>电影院座位预定</title>
<link rel="stylesheet" href="css/seat.css">
</head>
<body>
<div id="main">
<div class="seat">
<div id="seat-map">
<div id="front">屏幕</div>
<div id="seat-row">
</div>
</div>
<div id="booking-details">
<p>影片：<span>后来的我们</span></p>
<p>时间：<span>5月1日 21:00</span></p>
<p>票价：50元</p>
<p>座位：</p>
<ul id="selected-seats"></ul>
<p>票数：<span id="counter">0</span></p>
<p>总计：<b>￥<span id="total">0</span></b></p>
<button class="checkout-button" >确定购买</button>
<div id="legend"></div>
</div>
<div style="clear:both"></div>
</div>
</div>
<script>
var price = 50; // 定义票价
for (var i = 1; i <= 8; i++) {
for (var j = 1; j <= 8; j++) {
var one = document.createElement('div')
document.getElementById('seat-row').appendChild(one)
one.setAttribute('class', 'oneDiv')
// 定义变量num创建一个span标签
var num = document.createElement('a')
// 为变量num添加文本
num.innerText = i + '-' + j
// 为每个div定义id
one.setAttribute('id', 'seat' + i + j)
// 为座位添加点击事件监听器
one.addEventListener('click', function () {
this.style.backgroundColor = '#DE3239'
// 定义变量select通过获取当前点击div的id
var select = this.id
// 截取id第5个字符赋值给row
var row = select.slice(4, 5)
// 截取id第6个字符赋值给col
var col = select.slice(5, 6)
// 定义变量newUL通过id获取无序列表
var newUL = document.getElementById('selected-seats')
var lists = document.createElement('li')
// 为无序列表添加
newUL.appendChild(lists)
lists.innerText = row + '排' + col + '座'
// 添加数量和总数
var amount = document.getElementById('selected-seats').getElementsByTagName('li').length
var counter = document.getElementById('counter')
var total = document.getElementById('total')
counter.innerText = amount;
total.innerText = amount * price;
})
one.appendChild(num)
}
}
var counter=document.getElementById('counter');
if (counter.length >= 5) {
window.alert("您最多购买5张电影票");
}
</script>
</body>
</html>
说明没进if啊
不是元素的length大于5 是元素的innerHTML的值大于5时if才运行