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// Optional declaration var name: String? = "Alice" var age: Int? = nil // Force unwrap (crashes if nil - avoid) // print(age!) // would crash // Optional binding if let name = name { print("Hello, \(name)") } else { print("No name provided") } // Swift 5.7+ shorthand if let name { print("Name is: \(name)") } // guard let - early exit func greetUser(name: String?, age: Int?) { guard let name else { return } guard let age, age >= 0 else { return } print("Hello \(name), you are \(age)") } // Nil coalescing ?? let displayName = name ?? "Anonymous" let displayAge = age ?? 0 // Optional chaining ?. struct Address { var city: String } struct Person2 { var address: Address? } let person = Person2(address: Address(city: "Tokyo")) let city = person.address?.city // Optional("Tokyo") let upper = person.address?.city.uppercased() // Optional("TOKYO")
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