You'll find NJ's definitions of full-year and part-year residency on page 3 of this reference: https://www.state.nj.us/treasury/taxation/pdf/current/1040nri.pdf
A change of mailing address does not by itself constitute a change in residency, nor does a temporary absence from home for work or school purposes.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
