商品数量按钮加减
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
.box {
height: 100px;
width: 200px;
margin: 150px auto;
background-color: aquamarine;
text-align: center;
overflow: hidden;
border-radius: 10px;
}
.a {
height: 30px;
width: 80px;
border: 1px black solid;
text-align: center;
line-height: 30px;
margin: 15px auto 10px;
}
button {
height: 30px;
width: 40px;
}
</style>
</head>
<body>
<div class="box">
<div class="a">1</div>
<button class="jia">+</button>
<button class="jian">-</button>
</div>
<script>
var jia = document.querySelector(".jia");
var jian = document.querySelector(".jian");
var a = document.querySelector(".a");
var flag = 1;
jia.addEventListener("click", function () {
flag++;
a.innerHTML = flag;
});
jian.addEventListener("click", function () {
--flag;
a.innerHTML = flag;
if (flag <= 0) {
alert("最少购买一件");
a.innerHTML = 1;
jian.className = "disabled";
flag = 1;
}
});
</script>
</body>
</html>