Blazor Components and lifecycle MCQs ASP.NET

What is Blazor? A. A client-side web framework B. A server-side web framework C. Both A and B D. None of the above Answer: C Blazor WebAssembly runs on which of the following environments? A. Browser B. Server C. Cloud D. Local machine Answer: A Which programming language is primarily used in Blazor? A. Python B. C# C. JavaScript D. Java Answer: B Which method is used to initialize data or services in a Blazor component? A. OnInitializedAsync B. OnStart C. OnRender D. InitializeComponent Answer: A Which lifecycle method is invoked first in a Blazor component? A. OnInitialized B. OnParametersSet C. OnAfterRender D. OnRenderComplete Answer: A Blazor components are written in which file extension? A. .cshtml B. .razor C. .cs D. .html Answer: B Which directive is used to define a Blazor component? A. @page B. @component C. @inject D. @code Answer: A What is the purpose of the @inject directive in Blazor? A. For dependency injection B. To bind data C. To declare events D. To declare properties Answer: A How does Blazor handle JavaScript interop? A. Through .NET libraries B. By using JSInterop C. Using only Razor syntax D. By server-side event handling Answer: B Which lifecycle method is called when parameters are received by a Blazor component? A. OnParametersSetAsync B. OnInitializedAsync C. OnAfterRender D. OnStart Answer: A What does the StateHasChanged() method do in a Blazor component? A. Updates the page title B. Rerenders the component C. Terminates the component D. Changes the component’s state Answer: B Blazor WebAssembly works by compiling C# code into which format? A. Assembly code B. WebAssembly (Wasm) C. JavaScript D. HTML Answer: B What is the default event handling mechanism in Blazor? A. Through JavaScript functions B. Through Razor syntax C. Using events like @onclick D. By HTML event attributes Answer: C Which lifecycle method is called when the Blazor component has finished rendering for the first time? A. OnAfterRender B. OnInitialized C. OnStart D. OnRenderComplete Answer: A How can you pass data between Blazor components? A. By using services B. By using @code C. By using parameters D. By using events Answer: C What does Blazor use for two-way data binding? A. Event listeners B. The @bind directive C. JavaScript functions D. C# methods Answer: B Which of the following methods is NOT a Blazor lifecycle method? A. OnAfterRender B. OnInitialized C. OnBeforeRender D. OnParametersSet Answer: C What is the purpose of the @code block in a Blazor component? A. To import JavaScript libraries B. To define C# logic C. To define component CSS D. To handle HTTP requests Answer: B Which of the following is true for Blazor Server? A. It runs entirely on the client’s browser B. It maintains a SignalR connection with the server C. It is slower than Blazor WebAssembly D. It cannot interact with the DOM Answer: B How do you handle navigation in Blazor? A. Using the @route directive B. Using NavigationManager C. Using window.location D. Using @navigate directive Answer: B Which of these is NOT a valid Blazor lifecycle method? A. OnInitialized B. OnBeforeRenderAsync C. OnAfterRender D. OnDispose Answer: B Blazor can interact with JavaScript via what mechanism? A. JSBridge B. JavaScript Interop C. WebAssembly Proxy D. HTML5 API Answer: B What is the primary difference between Blazor WebAssembly and Blazor Server? A. Blazor Server relies on WebAssembly B. Blazor WebAssembly relies on server resources C. Blazor WebAssembly runs on the client-side D. Blazor Server is faster Answer: C Which directive is used to handle form events in Blazor? A. @onchange B. @oninput C. @onform D. @onsubmit Answer: D What is the main benefit of using Blazor components? A. Better integration with JavaScript B. Reusability and modularity C. It replaces Razor Pages D. It works only with WebAssembly Answer: B Which lifecycle method can be used to perform actions after the component has rendered? A. OnAfterRenderAsync B. OnInitialized C. OnBeforeRender D. OnDispose Answer: A How do you define a route in a Blazor component? A. @route B. @page C. @url D. @path Answer: B Blazor components are similar to which frontend technology? A. Angular Components B. React Components C. Vue.js Components D. All of the above Answer: D Which of the following is the correct way to inject a service in Blazor? A. @service B. @inject C. @dependency D. @provider Answer: B What is the typical file structure of a Blazor component? A. HTML + CSS B. Razor + C# C. JavaScript + HTML D. Razor + JavaScript Answer: B In Blazor, what does the @page directive define? A. A CSS class B. A navigation route C. A JavaScript function D. A Blazor component Answer: B Which method would you use to check if a Blazor component is disposing? A. OnDisposeAsync B. OnDispose C. DisposeComponent D. DisposeAsync Answer: B What event would you use to handle button clicks in Blazor? A. @onclick B. @onbutton C. @onpress D. @onhit Answer: A Blazor WebAssembly is ideal for: A. Full offline capabilities B. High server dependency C. Faster load times D. No dependency on client hardware Answer: A Which lifecycle method should be used for loading data asynchronously in Blazor components? A. OnAfterRenderAsync B. OnInitializedAsync C. OnParametersSetAsync D. OnDispose Answer: B Blazor components use which programming paradigm? A. Functional B. Object-Oriented C. Component-based D. Declarative Answer: C How can you invoke JavaScript from C# in a Blazor component? A. Using JavaScript.InvokeAsync B. Using JSBridge.Invoke C. Using JSInterop.InvokeAsync D. Using @js directive Answer: C What is the purpose of the RenderFragment in Blazor? A. It defines a section of the UI B. It is used for injecting CSS C. It handles component state D. It is used to define JavaScript logic Answer: A Which directive in Blazor is used to display child content in a parent component? A. @section B. @child C. @body D. @childcontent Answer: D In Blazor, how do you define a form field with two-way binding? A. <input @bind="property"> B. <input @bind-value="property"> C. <input @bind-field="property"> D. <input @field="property"> Answer: A Which of the following is true about Blazor’s dependency injection? A. It uses a service locator pattern B. It supports scoped services C. It doesn’t support transient services D. It only supports singletons Answer: B What is required to use a Blazor Server app? A. WebAssembly support B. Persistent SignalR connection C. LocalStorage D. Service Worker Answer: B How do you dispose of unmanaged resources in Blazor components? A. Using OnDispose B. Using Dispose C. Using Release D. Using Terminate Answer: B Blazor components can be compared to what in Angular? A. Directives B. Services C. Modules D. Components Answer: D Which lifecycle method is used for rerendering the UI after an update in Blazor? A. OnAfterRender B. OnBeforeUpdate C. OnUpdate D. OnAfterUIChange Answer: A Which directive is used to handle error boundaries in Blazor? A. @error B. @catch C. @trycatch D. @code Answer: B
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