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.
"null".
© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.18.5/dart-core/Null-class.html