Required Instance Methodswift 6.0.3Swift

decodeIfPresent(_:forKey:)

Decodes a value of the given type for the given key, if present.

func decodeIfPresent(_ type: UInt64.Type, forKey key: Self.Key) throws -> UInt64?

Parameters

type

The type of value to decode.

key

The key that the decoded value is associated with.

Returns

A decoded value of the requested type, or nil if the Decoder does not have an entry associated with the given key, or if the value is a null value.

Throws

DecodingError.typeMismatch if the encountered encoded value is not convertible to the requested type.

This method returns nil if the container does not have a value associated with key, or if the value is null. The difference between these states can be distinguished with a contains(_:) call.