# toUInt64() ``` func toUInt64() -> UInt64 ``` ## Discussion \abstract Convert a JSValue to a uint64_t. \discussion The JSValue is converted to an integer according to the rules specified by the JavaScript language. If the value is a BigInt, then the value is truncated to a uint64_t. --- 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)