# RandomNumberGenerator Implementations ## Topics ### Instance Methods [`func next() -> T`](/documentation/Swift/SystemRandomNumberGenerator/next()-2x0ly) Returns a value from a uniform, independent distribution of binary data. [`func next() -> UInt64`](/documentation/Swift/SystemRandomNumberGenerator/next()-70qj7) Returns a value from a uniform, independent distribution of binary data. [`func next(upperBound: T) -> T`](/documentation/Swift/SystemRandomNumberGenerator/next(upperBound:)) Returns a random value that is less than the given upper bound. --- 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)