Q. How do I cite online/electronic journal articles in the APA format?

From the Purdue Online Writing Lab (OWL):

Article From an Online Periodical

Online articles follow the same guidelines for printed articles. Include all information the online host makes available, including an issue number in parentheses.

Author, A. A., & Author, B. B. (Date of publication). Title of article. Title of Online Periodical, volume number(issue number if available). Retrieved from
http://www.someaddress.com/full/url/

Article From an Online Periodical with DOI Assigned

Author, A. A., & Author, B. B. (Date of publication). Title of article. Title of Journal, volume number, page range. doi:0000000/000000000000 or http://dx.doi.org/10.0000/0000