Angular Web Framework Cheat Sheet 2026

The 30 highest-yield Angular Web Framework facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In a web browser, how would you display dates? → Use the Angular pipe class in the template
2. Which Angular strategy checks only the current component and its ancestors when an input reference changes? → OnPush
3. When should you use `spyOn(service, 'method').and.returnValue(of(data))` in an Angular test? → When mocking an Observable-returning service method to control test data
4. What is the correct way to provide a custom async validator as a class implementing `AsyncValidator`? → Implement the `validate()` method returning Observable or Promise
5. Which Angular signal API creates a writable reactive value introduced in Angular 16+? → signal()
6. Which applications must be installed before you can download Angular? → Node.js
7. Which method on a Jasmine spy allows you to define what value it returns when called? → spy.and.returnValue()
8. In an Angular monorepo, what tool has become the industry standard for managing multiple projects? → Nx (formerly Nrwl)
9. What does `@ContentChildren(ItemComponent)` return inside a component? → A QueryList of all projected ItemComponent instances
10. What does the `async` pipe do when used in a template with an Observable? → Subscribes and automatically unsubscribes, rendering the latest value
11. Which lifecycle hook should you use to perform cleanup such as unsubscribing from Observables to prevent memory leaks? → ngOnDestroy
12. Which Angular build option is recommended for production deployments to minimize bundle size? → ng build --configuration=production (enables AOT, tree-shaking, minification)
13. Which Angular feature delays loading a module until a user navigates to its associated route? → Lazy loading
14. In Angular's template, what does the safe navigation operator (`?.`) prevent? → Null or undefined property access that would throw an error
15. What is the role of `pipe()` in RxJS? → Chains multiple operators together into a single transformation
16. What does Angular's `APP_INITIALIZER` token enable? → Running async setup tasks before the app fully bootstraps
17. Which Angular template syntax creates a local template reference variable for a DOM element? → #refName
18. What is the purpose of the computed() function in Angular Signals? → Derive a read-only value from one or more signals
19. Which Protractor (or Cypress) concept is equivalent to Angular's `waitForAngular` that ensures the app is stable before assertions? → Angular zone stability check
20. In an Angular monorepo with Nx, what is a `buildable` library's main benefit over a regular Nx library? → It generates its own compilable output, enabling incremental builds and build caching
21. According to Angular industry standards, when should you use OnPush change detection strategy? → For performance-sensitive components with immutable inputs or observable-driven data
22. What methods would you use to test your NativeScript Angular app? → Run it in a web-browser
23. What is the purpose of the Validators class? → Provides built-in validation functions like required, minLength, maxLength, and pattern
24. What is the recommended Angular approach for preventing broken links during single-page app navigation? → Use PathLocationStrategy with server-side fallback returning index.html for unknown routes
25. When using `async/await` in an Angular test instead of `fakeAsync`, what function must wrap the test callback? → async() from @angular/core/testing
26. What is the recommended Content Security Policy (CSP) practice for Angular applications to prevent XSS? → Use Angular's built-in sanitization and set strict CSP headers server-side
27. Which practice is considered a standard for managing environment-specific configuration in Angular? → Using environment.ts and environment.prod.ts with file replacements
28. Which observable on a FormControl emits only when the control's validation status changes? → statusChanges
29. What does 'providedIn: root' mean in an @Injectable() decorator? → The service is available application-wide as a singleton through the root injector
30. Which Angular CLI command generates a new library inside an existing workspace? → ng generate library my-lib