本文实例为大家分享了js实现购物车加减和价格运算的具体代码，供大家参考，具体内容如下
主要实现功能：购物车的加减，单件商品价格的运算，总价格的运算。价格保留两位小数。
<div class="content">
<div class="logo">
<img src="images/dd_logo.jpg"><span onclick="guan()">关闭</span>
</div>
<div class="cartList" id="zong">
<ul>
<li >¥21.90</li>
<li><input type="button" name="minus" value="-" onclick="jian()"><input type="text" name="amount" value="1" id="shang"><input type="button" name="plus" value="+" onclick="jia()"></li>
<li>¥<input type="text" name="price" value="21.90" id="yiqian"></li>
<li><p onclick="shou()">移入收藏</p><p onclick="shan()">删除</p></li>
</ul>
<ul>
<li >¥24.00</li>
<li><input type="button" name="minus" value="-" onclick="jian1()"><input type="text" name="amount" value="1" id="shang1"><input type="button" name="plus" value="+" onclick="jia1()"></li>
<li>¥<input type="text" name="price" value="24.00"id="erqian" ></li>
<li><p onclick="shan()">移入收藏</p><p onclick="shan()">删除</p></li>
</ul>
<ol>
<li id="totalPrice" > 0.00</li>
<li><span onclick="jie()">结 算</span></li>
</ol>
</div>
<h3 id="shijian">现在是：</h3>
</div>上边是html页面
以下是JS脚本
var price = 0.00;
var price1 = 0.00;
var price2 = 0.00;
function jian() {
var i = parseInt(document.getElementById("shang").valueOf().value) - 1;
if (i <= 0) {
i = 0;
}
document.getElementById("shang").valueOf().value = i;
price1 = 21.90 * i;
document.getElementById("yiqian").value=suan(price1);
zong();
}
function jia() {
var i = parseInt(document.getElementById("shang").valueOf().value) + 1;
document.getElementById("shang").valueOf().value = i;
price1 = 21.90 * i;
document.getElementById("yiqian").value=suan(price1);
zong();
}
function jian1() {
var i = parseInt(document.getElementById("shang1").valueOf().value) - 1;
if (i <= 0) {
i = 0;
}
document.getElementById("shang1").valueOf().value = i;
price2 = 24.00 * i;
document.getElementById("erqian").value=suan(price2);
zong();
}
function jia1() {
var i = parseInt(document.getElementById("shang1").valueOf().value) + 1;
document.getElementById("shang1").valueOf().value = i;
price2 = 24.00 * i;
document.getElementById("erqian").value=suan(price2);
zong();
}
function suan(number) {
price = price1 + price2;
if (isNaN(number)) {
return false;
}
number = Math.round(number * 100) / 100;
var s = number.toString();
var rs = s.indexOf(".");
if (rs < 0) {
rs = s.length;
s += ".";
}
while (s.length <= rs + 2) {
s += "0";
}
return s;
}
function zong() {
price = price1 + price2;
if (isNaN(price)) {
return false;
}
price = Math.round(price * 100) / 100;
var s = price.toString();
var rs = s.indexOf(".");
if (rs < 0) {
rs = s.length;
s += ".";
}
while (s.length <= rs + 2) {
s += "0";
}
document.getElementById("totalPrice").innerHTML=s;
}用的是最基本的方式，便于初学者看懂，特别是知识点有短板的额，基本上都能看懂。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程网。
