如何在javascript中增加页面加载中的跨度值？

Question

我想在javascript中增加标记之间的值 例如

<span class="quantity">1</span>

页面加载后

就像这样

<span class="shopp-quantity">2</span>

Answer 1

这与yesterday's：

大致相同

<span class="quantity"></span>
<script>
   localStorage['myid'] =
      document.getElementsByClassName('quantity')[0].innerHTML =
          parseInt(localStorage['myid'] || '0') + 1;
</script>