08-13-2016 10:33 AM - edited 08-13-2016 10:34 AM
I would recommend a user-defined format because you cannot suddenly turn a numeric variable into a character variable. But you can use a format to have the number 0 be displayed as No on any report output.
As Linus suggests, taking Programming 1 would help you with this task. In Programming 1, which is free, as self-paced e-learning, user-defined formats are covered in Lesson 5, entitled "Formatting Data Values" and in that lesson, there is a demo that covers "Specifying a User-Defined Format for a Numeric Variable".
ps you can activate the free Programming 1 class by setting up a SAS Profile and clicking Start Now on this page next to Programming 1: https://support.sas.com/edu/elearning.html?ctry=us&productType=library