<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
span {
min-width: 50px;
display: inline-block;
text-align: center;
color: red;
}
</style>
</head>
<body>
<p>
库存的最小值为0
</p>
<div>
库存：
<button data-plus="-1000">-1000</button>
<button data-plus="-100">-100</button>
<button data-plus="-10">-10</button>
<button data-plus="-1">-</button>
<span id="spanNumber">10</span>
<button data-plus="1">+</button>
<button data-plus="10">+10</button>
<button data-plus="100">+100</button>
<button data-plus="1000">+1000</button>
</div>
<script>
var btn = document.querySelectorAll("button")
for (var i = 0; i < btn.length; i++) {
btn[i].onclick = function() {
//获取要变化多少的数值
var num = parseInt(this.getAttribute("data-plus"))
// 获取当前库存
var now = document.getElementById("spanNumber")
var nowNum = parseInt(now.innerText)
if ((num + nowNum) > 0) {
now.innerText = nowNum + num
} else {
now.innerText = 0
}
}
}
</script>
</body>
</html> 0
点赞
收藏
分享
库存变更器
相关推荐
0 条评论
