计算购物车发票的总价

Question

In my code after users choose products and go to cart page, my cart page creates an html structure like this for all total prices of selected products: below here x indicates a number which is id of good that I fetch from Session, so every time these differ, also the number of fields changes every time based on user's choice

<span class="total-x"> some value</span>
<span class="total-x"> some value</span>
<span class="total-x"> some value</span>
.
.
.
.
<span class="total-x"> some value</span>

for example if cart gets id=3 form session after some other codes, page creates a field like this:

 <span class="total-3"> some value [has been computed]</span>

I want to sum up value of those field and put in a field like this:

<span id=total-all> </span> 

I ask for every which would lead me to over come this.

Answer 1

Try to use start with selector to identify that unknown class,

$("#total-all").text($("span[class^='total-']").get().reduce(function(a,b){
  return a + (+$(b).text());
},0));

DEMO