Swift Guard-let Statement

guard_let_test1.swift

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

let str: String? = giveMeAStringMaybe(true)
guard let unwrappedStr = str else {
    print("str is nil")
    // unwrappedStr is NOT accessible here
    return
}

// unwrappedStr is accessible here
print(unwrappedStr) // prints: "Yes!"