Instance Method

decodeIfPresent(_:forKey:)

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

Required. Default implementation provided.

Declaration

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

Parameters

type

The type of value to decode.

key

The key that the decoded value is associated with.

Return Value

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.

Discussion

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.