Dependency injection
shape
**IActionResult** is an interface in ASP.NET MVC (and also in ASP.NET Core MVC) that represents the result of an action method. In MVC (Model-View-Controller) applications, an action method in a controller returns an instance of IActionResult, which is used to define the response that will be sent back to the client (typically a web browser). @objc attribute in Swift is used to expose Swift code (such as methods, properties, or classes) to the Objective-C runtime. This allows Swift code to be used with Objective-C features, such as dynamic dispatch, selectors, KVO (Key-Value Observing), and targets for actions. The @objc attribute is essential for interoperability between Swift and Objective-C, especially when working with APIs that require Objective-C runtime features. UIViewController lifecycle refers to the sequence of methods that are called as a UIViewController object goes through different stages in its existence. These stages include creation, presentation, interaction, and destruction. Understanding the lifecycle helps developers manage view-related tasks, such as data loading, view configuration, and cleanup. unittest framework. Python's unittest is based on the xUnit pattern, which is widely adopted in other languages and frameworks (e.g., JUnit in Java, NUnit in C#). It provides a structured way to write and organize tests. Startup class is central to configuring and initializing the application. It provides two key methods, ConfigureServices and Configure, each with distinct roles in setting up the application's services and request processing pipeline.