If-else Javascript statement

Hi All,

I have two columns "strCellphone" and "strPhone". I want to create a new column "Phone" and Copy values from "strCellphone" but if "strCellphone" is empty, I want to copy values from "strPhone". I tried this with JS and it works on a normal editor but on Pentaho, I am not getting results as expected.

Here is my JS snippet:

var phone = strCellphone ;
if (!strCellphone.length){phone = strPhone;}

I have also tried various ways of checking null, empty like this one -> if (!strCellphone.length || strCellphone === ' '){phone = strPhone.getString();}

On Pentaho, The result is always assigned to if "strCellphone" even if it is empty.

Can you tell me what could be the problem? Thanks!