Table of Contents

Chapter 1: Accustoming Yourself to Objective-C          1

Item 1: Familiarize Yourself with Objective-C’s Roots  1

Item 2: Minimize Importing Headers in Headers  4

Item 3: Prefer Literal Syntax over the Equivalent Methods  8

Item 4: Prefer Typed Constants to Preprocessor #define  12

Item 5: Use Enumerations for States, Options, and Status Codes  17

Chapter 2: Objects, Messaging, and the Runtime         25

Item 6: Understand Properties  25

Item 7: Access Instance Variables Primarily Directly When Accessing Them Internally  33

Item 8: Understand Object Equality  36

Item 9: Use the Class Cluster Pattern to Hide Implementation Detail  42

Item 10: Use Associated Objects to Attach Custom Data to Existing Classes  47

Item 11: Understand the Role of objc_msgSend  50

Item 12: Understand Message Forwarding  54

Item 13: Consider Method Swizzling to Debug Opaque Methods  62

Item 14: Understand What a Class Object Is  66

Chapter 3: Interface and API Design         73

Item 15: Use Prefix Names to Avoid Namespace Clashes  73

Item 16: Have a Designated Initializer  78

Item 17: Implement the description Method  84

Item 18: Prefer Immutable Objects  89

Item 19: Use Clear and Consistent Naming  95

Item 20: Prefix Private Method Names  102

Item 21: Understand the Objective-C Error Model  104

Item 22: Understand the NSCopying Protocol  109

Chapter 4: Protocols and Categories         115

Item 23: Use Delegate and Data Source Protocols for Interobject Communication  115

Item 24: Use Categories to Break Class Implementations into Manageable Segments  123

Item 25: Always Prefix Category Names on Third-Party Classes  127

Item 26: Avoid Properties in Categories  130

Item 27: Use the Class-Continuation Category to Hide Implementation Detail  133

Item 28: Use a Protocol to Provide Anonymous Objects  140

Chapter 5: Memory Management         145

Item 29: Understand Reference Counting  145

Item 30: Use ARC to Make Reference Counting Easier  153

Item 31: Release References and Clean Up Observation State Only in dealloc  162

Item 32: Beware of Memory Management with Exception-Safe Code  165

Item 33: Use Weak References to Avoid Retain Cycles  168

Item 34: Use Autorelease Pool Blocks to Reduce High-Memory Waterline  173

Item 35: Use Zombies to Help Debug Memory-Management Problems  177

Item 36: Avoid Using retainCount  183

Chapter 6: Blocks and Grand Central Dispatch          187

Item 37: Understand Blocks  188

Item 38: Create typedefs for Common Block Types  194

Item 39: Use Handler Blocks to Reduce Code Separation  197

Item 40: Avoid Retain Cycles Introduced by Blocks Referencing the Object Owning Them  203

Item 41: Prefer Dispatch Queues to Locks for Synchronization  208

Item 42: Prefer GCD to performSelector and Friends  213

Item 43: Know When to Use GCD and When to Use Operation Queues  217

Item 44: Use Dispatch Groups to Take Advantage of Platform Scaling  220

Item 45: Use dispatch_once for Thread-Safe Single-Time Code Execution  225

Item 46: Avoid dispatch_get_current_queue  226

Item 47: Familiarize Yourself with the System Frameworks  233

Item 48: Prefer Block Enumeration to for Loops  236

Item 49: Use Toll-Free Bridging for Collections with Custom Memory-Management Semantics  243

Item 50: Use NSCache Instead of NSDictionary for Caches  248

Item 51: Keep initialize and load Implementations Lean  252

Item 52: Remember that NSTimer Retains Its Target  258

Index          265