# encodeIfPresent(_:forKey:configuration:) ``` mutating func encodeIfPresent(_ t: T?, forKey key: KeyedEncodingContainer.Key, configuration: C.Type) throws where T : EncodableWithConfiguration, C : EncodingConfigurationProviding, T.EncodingConfiguration == C.EncodingConfiguration ``` --- 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)