Editing S (programming language) (section)

===S4===
The latest version of the S standard is S4, released in 1998.<ref>{{cite web |title=The S System |last=Chambers |first=John |author-link=John Chambers (statistician) |date=January 1, 2001 |publisher=Bell Labs |url=http://ect.bell-labs.com/sl/S/ |archive-url=https://web.archive.org/web/20181014111802/http://ect.bell-labs.com/sl/S/ |archive-date=2018-10-14 }}</ref> It provides advanced object-oriented features. S4 classes differ markedly from S3 classes; S4 formally defines the representation and inheritance for each class, and has [[multiple dispatch]]: the generic function can be dispatched to a method based on the class of any number of arguments, not just one.<ref>{{Cite book |last=Wickham |first=Hadley |url=http://adv-r.had.co.nz/S4.html |title=Advanced R. |publisher=adv-r.had.co.nz |year=2019 |isbn=9781466586963 |section=S4 |access-date=2020-02-18}}</ref>