Angular Interview Practice

What dependency injection mechanism does Angular use in comparison to AngularJS?

1. An older mechanism with no hierarchy

2. A hierarchical and flexible system

3. No dependency injection

4. A simplistic global object

The correct answer is: A hierarchical and flexible system

Angular utilizes a hierarchical and flexible dependency injection system, which significantly enhances the way services and components can share dependencies and be configured. Unlike AngularJS, where the dependency injection was a flat system, Angular's design introduces a hierarchy that allows for services to be provided at different levels of the application structure, such as at the root, module, or component level. This hierarchical system means that a component can have dependencies injected that are scoped specifically to it, while also retaining access to shared services at higher levels of the hierarchy. This flexibility leads to better encapsulation and improved maintainability, as components can define their own dependencies without cluttering the global scope. Additionally, it allows for options like lazy loading of modules, which can optimize performance by only loading the required services when they are needed. In contrast, other options portray mechanisms that do not accurately reflect Angular's implementation. The absence of a dependency injection system or simplistically using a global object would not provide the benefits of modularity and encapsulation that the hierarchical approach enables. Overall, the design choices made in Angular aim to create a more robust framework that supports scalable applications.