# !=(_:_:) Returns a Boolean value indicating whether the left-hand-side argument is not `nil`. ``` static func != (lhs: borrowing Wrapped?, rhs: _OptionalNilComparisonType) -> Bool ``` ## Parameters `lhs` A value to compare to `nil`. `rhs` A `nil` literal. ## Discussion You can use this not-equal-to operator (`!=`) to test whether an optional instance is not `nil` even when the wrapped value’s type does not conform to the `Equatable` protocol. The following example declares the `stream` variable as an optional instance of a hypothetical `DataStream` type. Although `DataStream` is not an `Equatable` type, this operator allows checking whether `stream` wraps a value and is therefore not `nil`. ``` var stream: DataStream? = fetchDataStream() if stream != nil { print("The data stream has been configured.") } // Prints "The data stream has been configured." ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)