Sometimes it's useful to know what the invariant value is for your loop within a facelets loop.  I use ui:repeat a lot, but have seen <a href="http://aprilandjake.com/content/jsf-wont-submit-null-uirepeat/">some problems</a> with it in the past.   If you want to get the loop index for your ui:repeat, you may be disappointed.  Basically, it requires that you use a different looping mechanism.  A nice alternative is the a4j:repeat, which offers the same functionality, plus more awesomeness...



Enough talk, let's fight:

```jsp
<a4j:repeat var="email" id="repeatid" rowKeyVar="idx"
         value="#{collection}">
   #{idx},
</a4j:repeat>
```

If you loop four times, you should get 1,2,3,4,.

Another point of interest on these loops:

If you have jsf components within this a4j:repeat and need to know their exact id, the id on the loop will help this id be more predictable and readable.  For instance, in this situation:

```jsp
<h:form id="formid">
   <ui:repeat id="repeatid">
      <h:inputText id="textid" />
   </ui:repeat>
</h:form>
```

The id of the h:inputText component would be formid:repeatid:textid.  This is nice to know if you're trying to select dom elements by id in javascript.

Sometimes it's useful to know what the invariant value is for your loop within a facelets loop.  I use ui:repeat a lot, but have seen <a href="http://aprila