Abstract class at Flutter

In Flutter development, how we organize our code matters a lot. Abstract classes, which are an important part of this organization, help developers keep their code clean and organized by allowing them to focus on abstraction and encapsulation, two important concepts in Object-Oriented Programming (OOP).

In this article, I will cover

• What is an abstract class?
• Examples and Use Cases
• Benefits of abstract class.
• When should not use abstract class.
• Conclusion

Let's drive to detail.

What is abstract class?

An abstract class in programming acts like a template or a blueprint that other classes can use to create their own versions. Unlike regular classes, you can't create objects directly from an abstract class. Instead, it provides a foundation or a starting point for other classes to build upon. It's like a set of instructions that other classes follow to make their own unique versions.

Examples and Use Cases

Let's discuss specifics and bring the abstract to concrete with an example. We could have an abstract class called Character that defines basic properties and methods that all characters share, such as health, attack, and move.

abstract class Character {
  int health;
  int attack;

  void move();
  void attackEnemy();
}        

Next up, we create a child class that extends the Character base class, thus providing the required implementation for all the abstract methods.

class Warrior extends Character {
  @override
  void move() {
    print('Warrior moves swiftly!');
  }

  @override
  void attackEnemy() {
    print('Warrior attacks with sword!');
  }
}

class Mage extends Character {
  @override
  void move() {
    print('Mage teleports gracefully!');
  }

  @override
  void attackEnemy() {
    print('Mage casts fireball spell!');
  }
}        

In this example, Character is an abstract class that provides a blueprint for different types of characters. We define common properties and methods like health, attack, move, and attackEnemy. Then, we create specific classes like Warrior and Mage that inherit from Character and provide their own implementations for the abstract methods. This allows us to create instances of Warrior and Mage with their unique abilities, while still benefiting from the shared structure defined in the abstract class.

Benefits of abstract class

Abstract classes offer these benefits in programming:

1. Reuse Code: You can share common code among related classes.
2. Structure: They ensure that subclasses follow a set structure.
3. Flexibility: Subclasses can have their own unique implementations.
4. Polymorphism: Different objects can be treated the same way through the abstract class.
5. Enforce Rules: They make sure that certain methods must be implemented in subclasses.
6. Framework Building: They're handy for creating frameworks with consistent features.

In simple terms, abstract classes help keep code organized, easy to use, and consistent across different parts of a program.

When should not use abstract class

Avoid using abstract classes in these cases:

1. No Shared Behavior: If subclasses don't share common traits or actions, abstract classes add complexity without benefit.
2. Complexity vs. Help: If using abstract classes makes code more complicated without clear advantages, it might not be the best choice.
3. Single Inheritance Issue: Abstract classes limit subclasses to inheriting from only one parent. If you need more flexibility, consider other options like interfaces.
4. No Inherited Traits Needed: If subclasses don't need to inherit traits or actions from a common source, an abstract class isn't necessary.
5. Can't Create Instances: Abstract classes can't be directly used to create objects. If you need to create instances, look for alternatives.

Conclusion

Creating dependable Flutter apps isn't just about writing good code. It's also about how you design your app's structure. I hope this blog post has given you another helpful tip for organizing your Flutter apps better and improving your Flutter skills.

Keep coding, keep learning!

If you found this article helpful, let's connect on LinkedIn! I'm always open to expanding my network and discussing industry trends.

I'm Shahanaj Parvin, a Senior Flutter Developer with 8 years of experience in mobile app development and 5 years specializing in Flutter. With a strong background in creating innovative and user-friendly mobile applications, I'm passionate about pushing the boundaries of what's possible in Flutter development.

Feel free to connect with me here on LinkedIn, and don't hesitate to visit my Website for more information about my work. You can also explore my projects and contributions on GitHub at GitHub .

Looking forward to connecting with like-minded professionals and sharing insights on Flutter development and mobile app innovation.