What is control inversion?

Inversion of Control (IoC) is a design paradigm where the control flow of a program is transferred from user code to a framework or container. Instead of the code actively calling library methods, the framework calls methods provided by the user code at the appropriate time.

Main aspects:

• Separation of concerns: Components become less coupled.
• Improved testability: Dependencies can be easily replaced with mocks or stubs.
• More flexible design: Components are easier to modify and extend.

Implementation examples:

• DI (Dependency Injection): Injecting dependencies into components (via constructor, setters, or fields).
• Service Locator: The component actively requests dependencies from a central registry.
• Template methods: The algorithm is implemented in a base class, but steps can be overridden in subclasses.
• Event-driven programming: Code responds to external events rather than actively polling them.

IoC is often used in frameworks (e.g., React, Angular) to manage the lifecycle of components and their interactions.