Learn Objective C Programming for iOS Apps

Learn how pointers and arrays work in Objective-C, including the address, indirection, and contents operators, pointer types, zero-based arrays, and printing with printf using %f and %s.

Explore pointers and arrays in Objective-C by assigning integers, printing pointer values and addresses, and modifying pointed values; build and print Fibonacci numbers, square arrays, and C strings.

Explore how classes and objects in Objective-C define data types with properties and methods, distinguish interface (.h) from implementation (.m), and instantiate objects with alloc and init as pointers.

Examine defining an Objective-C class and its object, using an animal example with properties (name, legs, wings) and methods to set attributes and describe itself.

Explore objective-c properties and methods, including automatic getters and setters via self, dash versus plus methods, underscore ivars, and core types id and nil.

Explore how an animal class uses properties and methods, including a class method and an instance initializer, to create and describe objects with name, legs, and wings.

Explore inheritance and polymorphism in Objective-C by examining superclasses, method overriding, and dynamic binding, with examples of init, super calls, and structuring transportation, car, bike, and airplane classes.

Explore inheritance and polymorphism in Objective-C by modeling a transportation class with car and bicycle subclasses, overriding initializers, using super, and invoking a shared move method to demonstrate runtime behavior.

Learn how to declare object properties in Objective-C, manage memory with automatic reference counting, and use strong, weak, and atomic versus non-atomic properties to ensure proper memory and thread safety.

Explain NSString in Objective-C, including @ literals, init with string, and string with format, strong versus autoreleased objects, and mutable strings for in-place changes, plus converting between C strings and NSString.

Explore strings in Objective-C using literals and format constructors, build a greeting, log all strings, and convert between NSString and a C string with UTF8String and stringWithUTF8String.

Explore Objective-C arrays, including immutable NSArray and mutable NSMutableArray, index-based access, array literals, arrayWithObjects and nil terminator, and mutableCopy with capacity.

Learn to implement an NSArray-based log out class with a strings property and methods to log a string, log all strings, and use a mutable copy for adding items.

Explore NSSet, an unordered collection where each object appears once, and NSMutableSet for mutability, including creating sets from arrays and converting with init or setWithArray, plus NSCountedSet for per-object counts.

Observe an NSSet demo that builds immutable sets A and B to show their intersection and union, and illustrate mutable and counted sets with log outputs.

Examine Objective-C dictionaries as hash-like, unordered collections with object-for-key lookups, mutable variants, and literal forms, then explore counting, mutating, and p listable read-write patterns.

Demonstrate using Objective-C dictionaries to store and retrieve data with keys, convert to a mutable copy to add entries, and track repeated calls with a counted set for phone numbers.

Explore delegation and protocols in Objective-C, where a delegate handles events via a protocol, declares a delegate property, conforms to the protocol, and implements required methods.

Define a counter delegate protocol and a counter class that counts to a target, notifying the delegate when the count is divisible by 10, with a watcher implementing the method.

Discover Objective-C categories, a method-adding extension to classes, including naming conventions and interface/implementation syntax, to extend existing or own classes without modifying original code.

Explore creating an Objective-C category on NSString to add count and word count methods, import the category, and see how these new methods extend existing string functionality.

Explore how extensions hide properties from the public implementation, making them private to the class's internal implementation and accessible only within the class.

Discover how extensions, or anonymous categories, declare private properties and methods inside a class, making them inaccessible to the public API and triggering compiler warnings if not implemented.