Data Storage Recipes

Abstract

When working in iOS, one of the most important topics to understand is the concept, use, and implementation of persistence. Implementation of persistence refers to the idea of having information saved and retrieved, or persist, through the closing or restarting of an application. Just as pages from books can be read and re-read, even after closing and re-opening them, you can make use of certain key concepts in iOS to allow your information—from the simplest of values to the most complex of data structures—to stay stored in your device for indefinite periods of time. We cover a variety of methods of persistence throughout this chapter with different advantages, disadvantages, general uses, and complexities, so that you can develop a full understanding of the best method of storage for any given situation.