Classes

Dart Interfaces

Defining Interfaces

Dart interfaces use implements for contract enforcement.

What is an Interface in Dart?

An interface in Dart is a way to define a contract that classes can implement. Unlike some other languages, Dart does not have a specific keyword for defining interfaces. Instead, every class in Dart can act as an interface. When a class implements an interface, it must provide concrete implementations for all the methods declared in the interface.

Implementing Interfaces in Dart

In Dart, you use the implements keyword to implement an interface. This means the implementing class must override all the methods and properties defined in the interface class.

Here is a simple example of how to implement an interface in Dart:

Multiple Interfaces

Dart allows a class to implement multiple interfaces. This is useful when you want to ensure a class adheres to multiple contracts. When a class implements multiple interfaces, it must provide concrete implementations for all the methods from each interface.

Here's how you can implement multiple interfaces:

Why Use Interfaces?

Interfaces are crucial for defining consistent APIs, promoting code reuse, and enhancing testability. By using interfaces, you ensure that certain methods are implemented, which can help in maintaining a consistent code structure across your application.

Conclusion

Dart interfaces, through the use of the implements keyword, provide a powerful way to ensure that classes adhere to specific contracts. This facilitates better code organization, reusability, and maintainability. As you continue to work with Dart, leveraging interfaces will help you build more robust and scalable applications.

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