其中li为每个商品数目，li里的strong是商品数目，li里的em是商品单价，li里的input一个是减少数量，一个是增加数量，li里的span是该商品的总价，p为商品总合计，span是p的子元素，span0是商品总数，span1是总共价钱，span2为所选商品里最贵的一个，
var aLi = document.getElementsByTagName("li");
var aStrong = document.getElementsByTagName("strong");
var aEm = document.getElementsByTagName("em");
var oP = document.getElementsByTagName("p")[0];
var aSpan = oP.getElementsByTagName("span");
var number = 0;
var price = 0;
for(var i=0;i
Price(aLi[i]);
}
function Price(obj){
var aIn = obj.getElementsByTagName("input");
var oStrong = obj.getElementsByTagName("strong")[0];
var oEm = obj.getElementsByTagName("em")[0];
var oSpan = obj.getElementsByTagName("span")[0];
aIn[0].onclick = function(){
if(oStrong.innerHTML>0){
number--;
oStrong.innerHTML--;
price -= parseFloat(oEm.innerHTML);
oSpan.innerHTML = parseFloat(oEm.innerHTML)*oStrong.innerHTML + "元";
aSpan[0].innerHTML = number;
aSpan[1].innerHTML = price;
aSpan[2].innerHTML = getMax();
}
}
aIn[1].onclick = function(){
number++;
oStrong.innerHTML++;
price += parseFloat(oEm.innerHTML);
oSpan.innerHTML = parseFloat(oEm.innerHTML)*oStrong.innerHTML + "元";
aSpan[0].innerHTML = number;
aSpan[1].innerHTML = price;
aSpan[2].innerHTML = getMax();
}
}
function getMax(){
var arr = [];
for(var i=0;i
if(aStrong[i].innerHTML!=0){
arr.push(parseFloat(aEm[i].innerHTML));
}
}
return aStrong == 0 ? 0 : arr.sort(function(a,b){return b-a})[0];
}
