About this Course

Persisting data is a core skill for any iOS developer. This course will teach you three techniques for storing data to your device’s hard drive: NSUserPreferences for small amounts of data, the Sandbox for files and Core Data when you have to play in the Big Leagues!

Course Cost
Approx. 2 months
Skill Level
Included in Product

Rich Learning Content

Interactive Quizzes

Taught by Industry Pros

Self-Paced Learning

Student Support Community

Join the Path to Greatness

This free course is your first step towards a new career with the iOS Developer Program.

Free Course

iOS Persistence and Core Data

Enhance your skill set and boost your hirability through innovative, independent learning.

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Course Leads

Fernando Rodriguez

Fernando Rodriguez


Eden Shapiro

Eden Shapiro


Prerequisites and Requirements

This course assumes extensive iOS experience. Specifically, you’ve built several apps, know how to use core iOS libraries, and are familiar with networking and MVC design principles. Introduction to iOS App Development with Swift, UIKit Fundamentals, and iOS Networking with Swift are good courses to take if you need to familiarize yourself with these concepts.

The course also assumes basic familiarity with git. Specifically, you will need to be able to clone git repositories and checkout branches specific to each lesson. How to Use Git & GitHub is a great option if you need to brush up on these skills.

You will need access to a Mac computer running OS X 10.9 or later. However, you do not need an iPad or iPhone to complete the activities. All exercises can be completed using the iOS simulator built into Xcode.

See the Technology Requirements for using Udacity.

See the Technology Requirements for using Udacity.

Why Take This Course

Just like computers, your iPhone has two types of memory: main memory (RAM) and the hard drive. In all the apps you’ve written, you’ve interacted with RAM, but this memory is limited, and it’s important that the apps you design use it as efficiently as possible. To use the RAM efficiently it is important to be able to store data on the hard drive.

It is also important for your apps to maintain state when they are turned off. The apps you’ve built probably aren’t persistent, meaning that they don’t save their state to the device’s hard drive. As RAM is volatile, data is lost when the app stops running. In this course, you’ll learn how to persist the state of the device using NSUserDefaults and Core Data.

What do I get?
Instructor videosLearn by doing exercisesTaught by industry professionals