University:
Binghamton University
Course:
CS 541 | Game Dev for Mobile Platforms
Academic year:

2024
Views:

285

Pages:

4
Author:

F. Hidayat

Interface and Abstract Class Interface A class that implements an interface in Dart implies that the class must provide implementations for all methods declared in the interface. This means that all methods in the interface must be overridden by the class. The use of the implements keyword associates a class with an interface, and the class is required to provide a full implementation of the interface's declared methods. For example, in Dart, if we have a Shape interface that declares the area() method, a class like Circle can implement the interface by providing a concrete implementation for the area() method. By using the implements keyword, the class explicitly indicates its obligation to provide a full implementation according to the interface contract. So, basically, interfaces in Dart are a way to create a contract that ensures that the class implementing it provides all the methods declared in the interface. This allows for polymorphism and flexibility in the use of different classes that have a uniform contract. Example: //interface class Hero { armor() { print('000'); } hp() { print('000'); } } class Hero01 implements Hero { @override armor() { print('1000'); } @override hp() { print('800'); } } Note : If a class uses implements, then the class is required to override all methods in the superclass. How to use classes that have interface void main() { var h1 = Hero(); h1.armor(); h1.hp(); var h2 = Hero01(); h2.armor(); h2.hp(); } image 1 output from interface Abstract Class Abstract classes are used to create base classes that provide contracts for derived classes. Used with "extends", abstract classes cannot be made objects. And not all methods in the superclass must be overridden in the abstract class. Example: //abstract class abstract class Hero { armor() { print('000'); } hp() { print('000'); } } class Hero01 extends Hero { @override hp() { print('800'); } } How to use classes that have abstract class void main() { var h2 = Hero01(); h2.armor(); h2.hp(); } image 2 output from abstract class