Recently when mapping a flat file from a third party source, I needed to check whether some elements had been sent with any content or not.

In the source message these elements were being supplied in the form:

<comment />

I though I would try using the size functoid, assuming that it would return a size of 0 for these empty elements.  What actully happens is that the Size funtoid returned a size of 1 rather than the 0 I was expecting.

To get what I considered to be the correct output I needed to add a String Right Trim functoid before the Size functoid.  This then returned the "required" size of 0.