Null class

The reserved word null denotes an object that is the sole instance of this class.

The Null class is the only class which does not implement Object. It is a compile-time error for a class to attempt to extend or implement Null.

The language contains a number of specialized operators for working with null value. Examples:

e1!       // Throws if e1 is null.
e2 ?? e3  // Same as e2, unless e2 is null, then use value of e3
x ??= e4  // Same as x unless x is null, then same as `x = e4`.
e5?.foo() // call `foo` on e5, unless e5 is null.
[...? e6] // spreads e6 into the list literal, unless e6 is null.

Properties

hashCodeint
read-only, override
The hash code for this object. [...]
runtimeTypeType
read-only, inherited
A representation of the runtime type of the object.

Methods

noSuchMethod(Invocation invocation) → dynamic
inherited
Invoked when a non-existent method or property is accessed. [...]
toString() → String
override
Returns the string "null".

Operators

operator ==(Object other) → bool
inherited
The equality operator. [...]

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.13.0/dart-core/Null-class.html