HTML打折计算价格实现原理与脚本代码_HTML/Xhtml_网页制作



代码如下:







function calculator(){
var prices=document.getElementById("price");
var discounts=document.getElementById("number");
var pay;
var select=document.getElementById("payfunction");
if((prices.value>=0&&!isNaN(prices.value))&&(discounts.value>=0&&!isNaN(discounts.value))&&prices.value!=""&&discounts.value!="")
{
pay=prices.value*discounts.value;
switch(parseInt(select.value)){
case 1:pay=pay*0.5; break;
case 2:pay=pay*0.8; break;
case 3:pay=pay*0.6; break;
}
document.getElementById("result").value=pay;
alert("恭喜你，交易成功！");
}else
{
prices.focus();
prices.select();
alert("请输入正确的价格和数量(也不能为空)！");
}
}