How do nil-coalescing operators (??, ??=) work?

The nil-coalescing operator (??) in Swift provides a way to unwrap optionals for values that may be nil and substitute a default value if they are. This operator is essential for safely handling optional values without requiring extensive conditional checks. The operator can also be used in conjunction with the compound assignment operator (??=), which assigns a value to an optional if that optional is currently nil.

Here’s how the nil-coalescing operator works in Swift:

// Example of nil-coalescing operator in Swift
let optionalValue: String? = nil
let defaultValue = "Default String"
let result = optionalValue ?? defaultValue
print(result) // Output: Default String

// Example of nil-coalescing assignment operator
var anotherOptional: String?
anotherOptional ??= "Assigned String"
print(anotherOptional!) // Output: Assigned String