Smarty How to get an index during a loop

Most of the time we use the Ecshop foreach tag to cycle through the product, so the problem is that we generally use PHP loops with a variable to control the number of times and to get the index of each loop, such as I, how to get it when using foreach, very simple, We'll just define a name for it, as shown in the following example.

<!--{foreach name=top_goods from= $top _goods item=goods}-->
<div class= "Topgoodslist" >
<!--{if $smarty .foreach.top_goods.iteration==1}-->
<a href= "/{$goods. URL}" class= "Topsale1" title= "{$goods. name|escape:html}" ></a>
<!--{/if}-->

<!--{/foreach}-->

Here $smarty. Foreach.top_goods.iteration is the way to get an index.