Blazor is a web development framework that uses C# and Razor syntax. It allows developers to create interactive web UIs using C# instead of JavaScript. Blazor is still a relatively new technology, so during a job interview, you can expect questions about your experience and understanding of the framework. In this article, we will review some of the most common Blazor interview questions and provide guidance on how to answer them.
Blazor Interview Questions and Answers
Here are 20 commonly asked Blazor interview questions and answers to prepare you for your interview:
1. What is Blazor?
Blazor is a web framework that allows developers to create interactive web UIs using C# instead of JavaScript. Blazor uses a technique called “WebAssembly” to run C# code in the browser, which means that developers can write code once and have it work across multiple platforms. Blazor is still in preview, but it is already possible to create working applications with it.
2. Can you explain the architecture of a Blazor application?
Blazor is a web application framework that uses Razor components to build interactive web UIs. Blazor applications are composed of Razor components that handle user events and update the UI accordingly. Blazor uses a web assembly to run the application on the client side, and it can also be run on the server side.
3. How does WebAssembly work with Blazor?
WebAssembly is a low-level bytecode format that is designed to be run in web browsers. Blazor uses WebAssembly to run .NET code in the browser. This allows for .NET code to be run on the client-side, which can improve performance and responsiveness.
4. Can you explain how Blazor works under the hood?
Blazor is a web framework that allows developers to create interactive web UIs using C# instead of JavaScript. Blazor uses a technique called WebAssembly to compile C# code into a format that can be run in the browser. When a user interacts with a Blazor application, the C# code is downloaded and run in the browser, allowing the application to respond to user input in real time.
5. Why would we want to use Blazor for web development instead of other options like React or Angular?
Blazor provides a unique option for web development that uses C# and Razor syntax instead of JavaScript. This can be appealing for developers who are already familiar with C# and want to use it for web development, or who want to avoid having to learn a new language. Blazor also offers the ability to run on the server or the client, giving you more flexibility in how you deploy your applications.
6. How do you create a new project in Blazor?
You can create a new project in Blazor using the “dotnet new blazor” command.
7. How can we pass data from one component to another using Blazor?
There are a few different ways to pass data between Blazor components. One way is to use the @bind attribute. This will allow you to bind a value from one component to a property in another component. Another way is to use the @inject attribute. This will inject a service into a component, which can then be used to share data between components.
8. How can we share code between components using Blazor?
Blazor provides a number of ways to share code between components. One way is to use Razor Class Libraries (RCLs), which allow you to package up Razor components and share them across applications. Another way is to use JavaScript interop, which allows you to call JavaScript code from your Blazor components.
9. How can we render lists and tables in Blazor?
Blazor provides several different ways to render lists and tables. The most basic way is to use the built-in HTML elements, such as the
and
tags. However, Blazor also provides a number of other options for more complex rendering, including the @foreach and @if directives.
10. What are some ways to handle user input events in Blazor?
There are a few different ways to handle user input events in Blazor. One way is to use the @on{EVENT} attribute on an HTML element. This will handle the event in the browser and call a corresponding method on the component. Another way is to use the @bind{EVENT} attribute. This will handle the event in the browser and update a corresponding property on the component. Finally, you can use the EventCallback class. This will handle the event in the browser and call a corresponding method on the component, but it will also provide the event data as a parameter to the method.
11. How do you bind an event handler to a DOM element?
You can bind an event handler to a DOM element using the bind method. This method takes as its first argument the name of the event you want to bind to, and as its second argument the name of the event handler function.
12. How does routing work in Blazor?
Blazor uses a routing system that is similar to that used by ASP.NET Core. Routes are defined in the @page directive, and each route has a name and a template. The template is used to match the URL, and the name is used to generate the URL.
13. How can we manage state in Blazor?
Blazor uses a concept called “component parameters” to manage state. Essentially, any time a component is rendered, its parameters are passed in as attributes. These attributes can be used to store state information that can be accessed by the component. When the state of a component changes, the component is re-rendered with the new state information. This allows the component to keep track of its state and update its UI accordingly.
14. What is the best way to debug a Blazor application?
The best way to debug a Blazor application is to use the browser developer tools. You can access the developer tools in most browsers by pressing F12. With the developer tools, you can inspect the HTML and CSS of your application, and you can also set breakpoints in your JavaScript code.
15. What are some of the challenges associated with developing applications on Blazor?
One of the challenges with developing applications on Blazor is that it is a new technology and so there is not as much documentation or support available for it yet. Additionally, because Blazor uses webassembly, it can be challenging to debug applications and to understand how the different parts of the application interact with each other.
16. Are there any limitations that come with using Blazor?
Yes, there are some limitations that come with using Blazor. One such limitation is that Blazor only works with the latest versions of browsers, so older browsers will not be able to run Blazor applications. Additionally, Blazor is not yet able to take advantage of all of the features of modern browsers, so there are some things that it cannot do that other frameworks can.
17. What’s the difference between ASP.NET MVC and Blazor?
ASP.NET MVC is a traditional web framework that runs on the server, while Blazor is a new framework that runs in the browser via WebAssembly. Blazor uses C# and Razor syntax to create interactive web UIs.
18. Is it possible to run multiple Blazor apps within a single app? If yes, then how?
Yes, it is possible to run multiple Blazor apps within a single app. This can be done by using the Microsoft.AspNetCore.Components.WebAssembly.Hosting namespace. This namespace provides a way to build and configure a WebAssembly host that can run multiple Blazor apps.
19. Is it possible to access C# objects directly from JavaScript code? If yes, then how?
Yes, it is possible to access C# objects directly from JavaScript code. This can be done using the Blazor JavaScript interop library. The library allows you to call C# methods and access C# properties from JavaScript code.
20. Can you give me some examples of real-world projects built on Blazor?
Some examples of real-world projects built on Blazor are the Radzen platform, the Syncfusion Blazor DataGrid, and the Telerik UI for Blazor.
