Memory Management in Objective-C and Swift

Objectives

• You will be able to describe the reference counting memory management model used in Swift and Objective-C
• You will be able to describe what a retain cycle is, and how to use weak references to fix it
• You will be able to describe how memory management in closures and blocks works

Required Preclass Resources

• Memory Management Rules for Objective-C
• Automatic Reference Counting in Swift

Lesson Video

Video Challenges

Stretch Problem

Obj-C Highest Number in an Array

1. Make a new Objective-C Project
2. Write a method that prints the highest number in an array (that is stored as a property).
3. Change your method to take an array as a parameter and return the highest number. Once you do this, you can comment out your property and just make an array to use.
♦ Black Diamond
Modify your function so it also prints out the second highest number in the array.
Solution

Guided Project

Contacts

Contacts is a MRC Objective-C app so students can practice their understanding of reference counting concepts.

Project

• Rover

  Students will practice writing in Objective-C by building an app that allows a user to browse images provided by the NASA Mars Rover API. This app requires students to use concepts and APIs they already know, including MVC, table and collection views, custom model objects, property "observers", NSNotifications, NSURLSession, JSON parsing, etc.

  ReadMe

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