Swift provides the ?? operator for nil-coalescing. It unwraps Optionals and provides fallback or default values for the nil case. For instance, a ?? b unwraps optional a if it has a value and returns a default value b if a is nil.

In this example, if Optional a is not nil, the expression after the nil-coalescing operator is not going to be evaluated. Nil-coalescing is proper for scenarios where we can provide a fallback or default value.