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SkillSnap Official GuideUpdated 7/24/2026
Swift
Apple's modern powerhouse. Master Optionals, Protocol-Oriented Programming, and SwiftUI to build robust iOS and Mac apps.
Core Syntax & Safety
Constant (Preferred) / Variablelet / var
let x = 10 (Compiler guesses Int)Type Inference
Early exit (guard let x = opt else { return })Guard Statement
Execute block on scope exit (Cleanup)Defer
Compound values (404, "Error")Tuples
Optionals (The Heart of Swift)
Value might be nil? (Optional)
Provide default (name ?? "Guest")?? (Coalescing)
Safe unwrappingif let / guard let
Crash if nil (Avoid usage)! (Force Unwrap)
user?.profile?.name (Fail gracefully)Optional Chaining
Structs vs Classes
Value Type (Copied). Use by default.Struct
Reference Type (Shared). Use for identity.Class
Prevent inheritance (Performance boost)final class
Cleanup resources (Classes only)deinit
Modern Concurrency
Clean asynchronous codeasync / await
Unit of async workTask { }
Thread-safe state protectionActor
Ensure UI updates on main thread@MainActor
SwiftUI & Data
View-local simple state@State
Two-way connection to parent state@Binding
External state (ViewModel)@ObservedObject
Easy JSON serializationCodable
Memory Management (ARC)
Default reference (Keeps alive)strong
Prevents cycles (Becomes nil)weak
Prevents cycles (Non-optional, assumes existence)unowned
Capture list for closures[weak self]