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The nil-coalescing operator gives us another way to handle optional values by allowing us to provide a default value if the optional is nil. nil-coalescing uses the syntax optionalVal ?? defaultValue where optionalVal is some optional and defaultValue is the same type as the optional’s underlying type. If optionalVal is non-nil, this expression evaluates to optionalVal!.

var userLocation: String? = “Home”
let displayedLocation = userLocation ?? "Unknown"
print(displayedLocation) // Prints "Home"

If optionalVal is nil, this expression instead evaluates to defaultValue

var secondUserLocation: String?
let secondDisplayedLocation = secondUserLocation ?? "Unknown"
print(secondDisplayedLocation) // Prints "Unknown"

The nil-coalescing operator is great for giving a quick default value to an optional!

Instructions

Declare a variable named favoriteFood of type String? with an initial value of nil.

Print favoriteFood to the console. Notice the warnings that appear. Do you see a suggestion in the warnings that uses ???

Inside the print statement, use the nil-coalescing operator to give a default value of “No Favorite Food”.

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