The Timer class is a count-down timer that can be configured to fire events once or repeatedly.

False

True

Everything you can do with reduce() can always be done with fold() as well.

False

True

In Dart, deep copies are made with copyWith().

False

True

A function returning a Stream<T> (like below) doesn't need the return statement.

Stream test() async* {
  yield 10;
}

False

True

In Dart 2.10 and lower, typedef only works with functions.

False

True

The following code compiles successfully.

Navigator?.of(context).pushNamed('...');

False

True

In Dart there cannot be nested classes.

False

True

LayoutBuilder holds metadata about the physical screen. Widget properties (such as paddings) are not taken into account.

False

True

The following code compiles successfully.

class Example {
  late final int? a;
  Example(this.a);
}

False

True

The Key factory constructor returns an ObjectKey.

False

True

setState() always rebuilds the entire subtree.

False

True

A HydratedBloc (from 'flutter_bloc') cannot support undo and redo actions.

False

True

The embedder, written in C++, is the real core of Flutter.

False

True

The following code compiles successfully.

class Example {
  String? _name;
  Example.named(this._name);
}

False

True

SOLID principles are valid for any programming language, not only Dart.

False

True

The following code compiles successfully.

class Super {
  int a;
  Super(this.a);
}

class Sub extends Super {
  int b;
  Sub(int b) : super(b*b), this.b = b;
}

False

True

The Flutter inspector shows janky frames with red bars.

False

True

The fromJson(Map<String, dynamic>) and toJson() methods are used on classes to convert them from and to JSON.

False

True

Flutter's engine is exposed to the developer via dart:ui.

False

True

In the navigator 2.0 update, pop() doesn't return a value anymore.

False

True

This is a smart casts .

if (apple is Fruit) {
  (grapes as Fruit).color = "Green";
}

False

True

AnimatedWidget is a subtype of AnimatedBuilder.

False

True

Which type of map doesn't exist?

SplayTreeMap

LinkedHashMap

SplayHashMap

HashMap

In order to work correctly, two Hero widgets must have the same tag property.

False

True

yield* is used to "pause" the execution and start emitting values from another stream.

False

True