R 4 Quick Syntax Reference: A Pocket Guide to the Language, API's and Library

© The Author(s), under exclusive license to APress Media, LLC, part of Springer Nature 2022

M. TollefsonR 4 Quick Syntax Referencehttps://doi.org/10.1007/978-1-4842-7924-3_5

5. Classes of Objects

Margot Tollefson¹  

(1)

Vanward Statistics, PO Box 286, 612 Teneyck Avenue, Stratford, IA, 50249-0286, USA

 

In R, objects belong to classes as well as types and modes. Classes tell something about what the object contains. All objects belong to at least one class. The S3, S4, and Reference Class object systems differ regarding classes. In S3, there are specific classes into which an R object falls. In S4, the user defines a class for an S4 object. Classes in S3 are called informal classes, whereas classes in S4 are called formal classes. In both systems, classes ...