None<A> class

Represents a missing value.

Inheritance

• Object
• Option<A>
• None

Available extensions

• MapOptionExtension

Constructors

None()

const

Properties

hashCode → int

The hash code for this object.

no setter, override

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

extract<T>(K key) → Option<T>

Available on Option<Map<K, dynamic>>, provided by the MapOptionExtension extension

Return an Option that conditionally accesses map keys, if they match the given type. Useful for accessing nested JSON.

extractMap(K key) → Option<Map<K, dynamic>>

Available on Option<Map<K, dynamic>>, provided by the MapOptionExtension extension

Return an Option that conditionally accesses map keys, if they contain a map with the same key type. Useful for accessing nested JSON.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toJson(Object? toJsonT(A v)) → Object?

Adds support for the json_serializable package.

override

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

override