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Test: Swift - Summary of ?, !, and ?? in Optionals 3. Which of following is an example of Optional Chaining?
Results Congratulations! Correct Answer. You Answered: None. If you took the test, your answer will show up here. Correct Answer: var count = city?.nickname?.characters.count Explanation In Optional Chaining, ? is used on optionals (variables, constants, methods returning optionals, subscripts returning optionals, etc.) in a chain to return nil (without crashing) for the entire expression.Take the Test Take the complete test on this topic. You will be able to review answers to questions and get a test score.
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Summary of three operators (?, !, ??) used in optionals in Swift.
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Test on the usage of various Optionals operators (?, !, ??) in Swift
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