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KEEPING YOUR PROGRAMS SAFE WITH OPTIONALS
In this chapter, we’ll cover a very cool feature in Swift: optionals. Optionals are variables that can either have a value or no value at all. Swift is different from many programming languages because normal constants and variables must have a value. This makes Swift a safe language because it prevents your code from failing when a variable is expected to have a value but one hasn’t yet been set.
However, there will be times when you need to create a variable but don’t have a value for it yet. In these cases, you can use an optional.
WHAT IS AN OPTIONAL?
You can think of an optional as a box that either ...
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