Hands on swift 5.3 doc
https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html
✅ The Basics
✅ Basic Operators
✅ Strings and Characters
✅ Collection Types
✅ Control Flow
✅ Functions
✅ Closures
✅ Enumerations
✅ Structures and Classes
✅ Properties
✅ Methods
✅ Subscripts
✅ Inheritance
🤫 Initialization
✅ Deinitialization
✅ Optional Chaining
📝 Error Handling
📝 Type Casting
📝 Nested Types
📝 Extensions
📝 Protocols
📝 Generics
📝 Opaque Types
📝 Automatic Reference Counting
📝 Memory Safety
📝 Access Control
📝 Advanced Operators