Swift If-let Statement

if_let_test1.swift

func giveMeAStringMaybe(_ maybe: Bool) -> String? {
    return maybe ? "Yes!" : nil
}

let str: String? = giveMeAStringMaybe(true)
if let unwrappedStr = str {
    print(unwrappedStr is String) // prints: true
    print(unwrappedStr) // prints: "Yes!"
} else {
    print(str) // prints: nil
}

// unwrappedStr is no longer accessible, only str