Kas saaksite üles loetleda peamised disainimustrid ja kirjeldada nende eesmärki?

Main design patterns and their purpose:

• Singleton (Singleton): ensures that a class has only one instance and provides a global access point to it.

• Observer (Observer): allows objects to subscribe to events of another object and receive notifications about changes.

• Factory Method (Factory Method): defines an interface for creating an object, but allows subclasses to alter the type of objects that will be created.

• Decorator (Decorator): dynamically adds responsibilities to objects by wrapping them.

• MVC (Model-View-Controller): divides the application into three components — model, view, and controller — to facilitate maintenance and extension.

These patterns help create a flexible, extensible, and maintainable architecture for applications.