Optional<T> class

Copyright (c) 2026 Netmera Research.

Immutable optional value: distinguishes "not set" from "set to null".

• Optional.of — value is present
• Optional.absent — explicitly no value (e.g. set to null)
• A field being null (no Optional at all) means "never set"

Constructors

Optional.absent()

Optional with no value (explicitly set to null).

factory

Optional.fromNullable(T? value)

From nullable: null → absent, non-null → of.

factory

Optional.of(T value)

Optional containing the given value (must not be null; use absent for null).

factory

Properties

hashCode → int

The hash code for this object.

no setter, inherited

isPresent → bool

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

valueOrNull → T?

The value if present, otherwise null.

no setter

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited