There are many design patterns used in mobile app development, but some of the most common ones are:
- Model-View-Controller (MVC) pattern: This pattern separates the app into three parts: the model (data and business logic), the view (user interface), and the controller (mediates between the model and view).
- Model-View-ViewModel (MVVM) pattern: This pattern is similar to MVC but separates the view and model using a mediator called the view model. The view model provides an interface to the view and exposes properties and commands that the view can bind to.
- Singleton pattern: This pattern ensures that only one instance of a class is created and provides a global point of access to that instance.
- Observer pattern: This pattern is used when one object (the subject) wants to notify a set of other objects (the observers) when its state changes. This is often used in user interfaces to update the view when the underlying data changes.
- Decorator pattern: This pattern allows behavior to be added to an individual object, either statically or dynamically, without affecting the behavior of other objects from the same class.
- Adapter pattern: This pattern converts the interface of a class into another interface that the client expects. This is often used to adapt third-party libraries to the needs of an app.
- Facade pattern: This pattern provides a simplified interface to a larger body of code, hiding its complexity and making it easier to use.
These patterns are widely used in mobile app development to solve common problems and improve the quality, scalability, and maintainability of code.