20 Angular Routing Interview Questions and Answers

Angular Routing is a popular framework used for developing single-page web applications. If you are applying for a position that involves Angular Routing, it is important to be prepared for questions about this framework. In this article, we review some of the most common Angular Routing interview questions and provide tips on how to answer them.

Angular Routing Interview Questions and Answers

Here are 20 commonly asked Angular Routing interview questions and answers to prepare you for your interview:

1. What is Angular routing?

Angular routing is a way to manage the different states or views of an Angular application. It lets you define different URLs for different parts of your app, and map those URLs to the corresponding Angular components. Angular routing also lets you specify which components should be displayed when a user navigates to a specific URL.

2. Can you list the main features of Angular Router?

The Angular Router is a powerful routing library that allows developers to create single-page applications with rich routing capabilities. The router is easy to use and can be configured to work with a variety of different backends. The router also supports lazy loading, which can improve the performance of large applications.

3. How do you define a route in an Angular application?

In Angular, a route is defined by using the @RouteConfig decorator. This decorator takes an array of route configurations, where each route configuration is an object that specifies the path of the route, the component to be used for the route, and any child routes that the route may have.

4. Can you explain how to pass parameters via routes in Angular?

In Angular, you can pass parameters to routes in order to specify which data you would like to access or manipulate. To do this, you will need to use the routerLink directive. The routerLink directive takes an array of parameters, where each parameter is a key-value pair. The key is the name of the parameter, and the value is the data you wish to pass.

5. What are auxiliary routes? When would you use them?

Auxiliary routes are used to add additional functionality to an Angular application beyond the normal routing. They can be used to create child routes, lazy-loaded routes, or to provide additional data to a component.

6. What’s the difference between routerLink and href? Which one should be preferred when defining routes?

The main difference between routerLink and href is that routerLink is used to define routes within your Angular application, while href is used to define routes to external resources. When defining routes within your Angular application, you should always use routerLink to ensure that the routing logic is handled correctly.

7. How can we make use of wildcard routes with Angular?

Wildcard routes are useful for situations where we want to redirect users to a specific page if they enter an incorrect URL. For example, if we have a website with the URL www.example.com/products, and a user tries to go to www.example.com/product, we can redirect them to the correct page using a wildcard route.

8. In what ways can we redirect requests using Angular routers?

There are a few ways to redirect requests using Angular routers. One way is to use the routerLink directive. This directive can be used on anchor tags and will automatically generate the href attribute based on the route you provide. Another way to redirect requests is to use the router.navigate method. This method takes an array of commands and a navigation extras object. The navigation extras object can be used to specify things like query parameters and fragment identifiers.

9. Can you give me some examples of situations where Route Guards might be useful?

Route Guards can be used in a number of situations in order to protect routes from unauthorized access. For example, you might use a Route Guard to prevent a user from accessing a route if they are not logged in, or if they do not have the appropriate permissions.

10. Can you show me an example of implementing Lazy Loading in an Angular app?

Lazy loading is a technique used in Angular to load modules only when they are needed, instead of loading them all upfront. This can improve the performance of an Angular app, especially if there are a lot of modules. To implement lazy loading, you can use the loadChildren() method in the route configuration. This method takes a function that returns a promise for the module that should be loaded. The module will then be loaded when the route is accessed.

11. Are there any issues associated with using nested or child routes? If yes, then what are they?

Yes, there are some potential issues associated with using nested or child routes. One such issue is that if a child route is deactivated, then its parent route will also be deactivated. This can lead to unexpected behavior for the user. Additionally, if a child route is not properly configured, it can cause problems with the routing of the entire application.

12. What does lazy loading mean?

Lazy loading is a technique used in Angular to load modules only when they are needed, instead of loading all modules upfront. This can improve the performance of an Angular application, since the browser will not need to load unnecessary code. Lazy loading is typically used for large applications with many modules, where not all modules need to be loaded immediately.

13. What’s the difference between loadChildren and children in Angular?

The difference between loadChildren and children in Angular is that loadChildren is used to lazy-load components, while children is used to eagerly load components. With loadChildren, the component is not loaded until the user navigates to the route. With children, the component is loaded immediately.

14. Why is it necessary to implement authentication checks for certain routes?

Authentication checks are necessary for certain routes in order to ensure that only authorized users are able to access the information that is behind those routes. If the wrong people were able to gain access to certain information, it could lead to serious security implications.

15. What happens if two routes have different path values but share the same data value?

If two routes have different path values but share the same data value, then the router will use the first route that it encounters with a matching data value. This can cause unexpected behavior, so it is generally best to avoid having two routes with the same data value.

16. How can I get the URL of the current page in my Angular application?

You can use the Router service to get the URL of the current page in your Angular application. The Router service has a method called routerState that returns an observable of the current router state. You can subscribe to this observable to get the current URL.

17. Can you describe you how navigation works in Angular?

Angular uses a component-based router to handle navigation. This means that there is a designated component for each route, and the router will automatically render the correct component for the current route. The router also takes care of automatically updating the URL to match the current route, and it can also handle things like passing parameters to components.

18. What’s the best way to handle errors while resolving routes in Angular?

The best way to handle errors while resolving routes in Angular is to use the error handler function provided by the $route service. This function will take care of any errors that occur during route resolution, and will provide a helpful error message to the user.

19. From a performance perspective, which approach should be preferred: Lazy Loading or Preloading?

Lazy loading is the preferred approach from a performance perspective. This is because it allows the application to only load the necessary components as they are needed, which can help to improve loading times. Preloading, on the other hand, loads all components upfront regardless of whether or not they are actually needed, which can lead to longer loading times.

20. Is it possible to render specific components based on the route in Angular? If yes, then how?

Yes, it is possible to render specific components based on the route in Angular. This can be done using the router-outlet directive. The router-outlet directive tells the router where to place the components that are rendered based on the current route.