Objective CStudy Notes

ARC and Memory Management

How Automatic Reference Counting manages object lifetimes in Objective-C, and how it relates to the manual retain/release model it replaced.

Blocks in Objective-C

Learn how Objective-C blocks capture surrounding variables as closures, how __block and __weak change capture behavior, and how to avoid retain cycles.

Building a Simple iOS App in Objective-C

A hands-on walkthrough of scaffolding, wiring, and running a basic iOS app entirely in Objective-C, from project setup to a working table view.

Categories and Extensions

How Objective-C categories add methods to existing classes without subclassing, and how class extensions expose private, writable state.

Class Methods vs Instance Methods

Learn the difference between Objective-C's + class methods and - instance methods, and when to use each in real-world class design.

Classes and Objects in Objective-C

How Objective-C classes are declared with @interface/@implementation, and how objects are created via alloc and init.

Cocoa Touch and UIKit Basics

An introduction to the Cocoa Touch layer, UIKit's view hierarchy, view controller lifecycle, and how touch events and Auto Layout combine to build iOS interfac…

Conditionals in Objective-C

Learn how Objective-C branches program flow using if/else, the ternary operator, and switch statements, and how BOOL and nil interact with truthiness.

Error Handling with NSError

The conventions and patterns Objective-C uses for reporting recoverable errors via NSError, as distinct from exceptions for programmer errors.

Grand Central Dispatch Basics

How GCD's queues, blocks, groups, and barriers provide a simple, C-based model for concurrency in Objective-C, and the deadlock traps to avoid.

Inheritance in Objective-C

How Objective-C's single-inheritance class hierarchy works, including method overriding, calling super, and designated initializers.

Installing Xcode and Setup

How to install Xcode, set up a new Objective-C project, and compile Objective-C from the command line.

Loops in Objective-C

Understand Objective-C's for, while, do-while, and fast enumeration (for-in) loops, and how break and continue control iteration.

Methods and Message Passing

Explore how Objective-C methods work as messages sent to objects at runtime, including selectors, method signatures, and dynamic dispatch.

NSArray, NSDictionary, and Collections

Working with Objective-C's core collection classes — NSArray, NSDictionary, NSSet — including mutability, enumeration, and common pitfalls.

NSString and String Handling

How Objective-C represents and manipulates text with NSString and NSMutableString, including encoding, formatting, and common gotchas.

Objective-C and Swift Interoperability

How Objective-C and Swift code coexist in the same Xcode target, and the annotations and conventions that make the bridge between them safe and idiomatic.

Objective-C Best Practices

Practical, battle-tested conventions for writing safe, readable, and maintainable Objective-C code, from memory management to naming and API design.

Objective-C Data Types

Objective-C's primitive types, Foundation typedefs like BOOL and NSInteger, and object types accessed through pointers.

Objective-C Interview Questions

Commonly asked Objective-C interview questions covering memory management, runtime behavior, protocols, and blocks, with explanations of what strong answers co…

Objective-C Quick Reference

A condensed reference for Objective-C syntax, common Foundation types, memory attributes, and idioms you'll reach for constantly while coding.

Objective-C Runtime and Dynamism

How Objective-C's message-passing runtime enables introspection, method swizzling, and associated objects, and the risks that come with that power.

Objective-C Syntax and Variables

How Objective-C extends C syntax with object messaging, and how primitive versus object variables are declared.

Objective-C vs Swift

A practical comparison of Objective-C and Swift covering syntax, memory management, interoperability, and when each language is the right choice on Apple platf…