What is optional chaining?

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Main Source: 🔗 Ace the iOS Interview

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TL/DR

Optional chaining is a convenient way of unwrapping multiple Optional properties sequentially. If any of the Optional values in theexpression resolve tonil, the entire expression will resolve tonil.

Consider the following expression involving multipleOptionalproperties:

user?.isAdmin?.isActive

If user or isAdmin or isActive is nil, the entire expression becomes nil. Otherwise, isActive will return the unwrapped value.

This is much more readable than using multiple guard and if let statements to break down a sequence of Optional values.