String concatenation in jsf

There is no string concatenation in pure JSF, but I found little hack to work this around.

Imagine, you have to concat "con" and "cat" strings.
Declare two ui params:

<ui:param name="string1" value="con" />
<ui:param name="string2" value="cat" />

Now declare the third param:

<ui:param name="result" value="#{string1}#{string2}" />

Voila :) you can use #{result} where you need.