s:for

Iterate over a group of variables.

INPUT
<s:mset>
    user 1 => Sed
    user 2 => Amin
    user 3 => Ted
</s:mset>
<s:for each="user *" as="awesome user">
    <s:put> awesome user </s:put>, 
</s:for>
OUTPUT
Sed, Amin, Ted,
each=""  
Required

A wildcard that is used to find variables to loop over.

as=""  
Required

On each iteration, the value of the current found variable is assigned to as.

key=""  

On each iteration, the name of the current found variable is assigned to key.