What is data binding in Blazor?
A. A way to bind C# variables to UI elements
B. A way to bind JavaScript to HTML
C. A method to bind CSS to components
D. A mechanism to bind SQL queries
Answer: A
Which directive is used for one-way data binding in Blazor?
A. @bind-value
B. @one-way
C. @bind
D. @if
Answer: C
What does two-way data binding mean in Blazor?
A. Data flows from the UI to the model
B. Data flows from the model to the UI
C. Data flows both ways between UI and model
D. Data is only updated on button click
Answer: C
How do you achieve two-way data binding for a form input in Blazor?
A. Using @bind
B. Using @value
C. Using @databind
D. Using @model
Answer: A
What is the purpose of @bind directive in Blazor?
A. To handle form validation
B. To synchronize UI and model data
C. To call JavaScript functions
D. To inject services
Answer: B
Which event is automatically wired in a two-way data binding scenario?
A. oninput
B. onclick
C. onchange
D. onsubmit
Answer: C
In Blazor, which event is used for binding an input field dynamically?
A. onchange
B. oninput
C. onsubmit
D. onblur
Answer: B
What is the default binding behavior of Blazor for a text input field?
A. One-way binding
B. Two-way binding
C. No binding
D. Automatic state binding
Answer: B
What does the @bind-Value:event syntax allow you to do?
A. Change the bound property dynamically
B. Bind the input field to a custom event
C. Handle validation in Blazor
D. Bind CSS dynamically
Answer: B
Which Blazor feature supports two-way binding without JavaScript?
A. Razor components
B. SignalR
C. WebAssembly
D. .NET Interop
Answer: A
What is the correct way to bind a checkbox in Blazor?
A. <input type="checkbox" @bind="isChecked">
B. <input type="checkbox" @bind-value="isChecked">
C. <input type="checkbox" @bind-check="isChecked">
D. <input type="checkbox" @bind-checked="isChecked">
Answer: A
Which directive should be used to bind a select dropdown in Blazor?
A. @bind-value
B. @bind
C. @databind
D. @value
Answer: B
In Blazor, how do you bind an input of type number to a C# integer?
A. <input type="number" @bind="numberValue">
B. <input type="number" @bind-value="numberValue">
C. <input type="number" @bind-int="numberValue">
D. <input type="number" @bind-number="numberValue">
Answer: A
What is required for data binding in Blazor components?
A. Property or field in the component
B. Method in JavaScript
C. External library
D. Dynamic Razor views
Answer: A
How does Blazor handle two-way binding between parent and child components?
A. Through EventCallback
B. Using @bind only
C. Using JSInterop
D. Through Parameter directive
Answer: A
Which directive is used for one-way binding from parent to child component in Blazor?
A. @child-content
B. @parameter
C. @bind-value
D. @databind
Answer: B
Which type of event must be specified for two-way binding to occur on an input element in Blazor?
A. onchange
B. onclick
C. onmouseover
D. onblur
Answer: A
How do you bind a date input field to a C# DateTime property in Blazor?
A. <input type="date" @bind="dateValue">
B. <input type="datetime" @bind="dateValue">
C. <input type="date" @bind-datetime="dateValue">
D. <input type="datetime-local" @bind="dateValue">
Answer: A
What is the default value when binding a select dropdown list in Blazor?
A. The first option
B. The last option
C. The option with selected attribute
D. No default value
Answer: A
Which binding mode should be used for binding a list of items in a Blazor component?
A. One-way binding
B. Two-way binding
C. Data binding
D. Event binding
Answer: A
What type of binding is used when displaying a value but not allowing modification?
A. One-way data binding
B. Two-way data binding
C. Property binding
D. Event binding
Answer: A
Which lifecycle method ensures that the bound data is loaded when a Blazor component is initialized?
A. OnInitializedAsync
B. OnParametersSet
C. OnAfterRender
D. StateHasChanged
Answer: A
Which of the following is true for @bind:event syntax in Blazor?
A. It changes the default binding event
B. It binds data to custom properties
C. It handles data updates asynchronously
D. It automatically calls StateHasChanged
Answer: A
What happens if the bound property in Blazor is not updated when the value changes in the UI?
A. An error occurs
B. State is not refreshed
C. Data gets out of sync
D. The page rerenders
Answer: C
What is the purpose of the @bind:get directive in Blazor?
A. It specifies a custom getter for binding
B. It sets the binding event
C. It disables two-way binding
D. It handles event propagation
Answer: A
How does @bind handle data binding for checkboxes in Blazor?
A. It binds the checked property
B. It binds the value property
C. It uses event listeners
D. It uses JavaScript interop
Answer: A
Which event triggers the update in the model when using two-way data binding in a Blazor input element?
A. onchange
B. onclick
C. onkeypress
D. onfocus
Answer: A
In Blazor, how can you bind a textarea input for two-way binding?
A. <textarea @bind="text">
B. <textarea @bind-value="text">
C. <textarea @bind-input="text">
D. <textarea @bind-textarea="text">
Answer: A
How can you prevent an input value from being updated during two-way data binding?
A. By using readonly attributes
B. By using one-way binding
C. By setting @bind-Value:event="oninput"
D. By calling StateHasChanged()
Answer: A
In Blazor, how do you handle input validation during data binding?
A. Using EditForm with validation attributes
B. By overriding the StateHasChanged method
C. Using custom JavaScript functions
D. By setting the input type to text
Answer: A
What is the effect of two-way binding on performance in Blazor?
A. Slower performance due to rerendering
B. Faster updates due to event handling
C. No effect on performance
D. It depends on the complexity of data
Answer: A
Which directive is used to bind a child component property to the parent component?
A. @bind-Parent
B. @bind-value
C. @ChildBind
D. @Parameter
Answer: D
What is the correct syntax to bind a radio button in Blazor?
A. <input type="radio" @bind="selectedValue">
B. <input type="radio" @bind-value="selectedValue">
C. <input type="radio" @bind-checked="selectedValue">
D. <input type="radio" @bind-radio="selectedValue">
Answer: A
In Blazor, what is the purpose of EventCallback?
A. To invoke events between parent and child components
B. To bind an event to JavaScript
C. To manage one-way data binding
D. To validate form inputs
Answer: A
Which lifecycle method is invoked when the data binding parameters are set in Blazor?
A. OnParametersSetAsync
B. OnInitializedAsync
C. OnAfterRenderAsync
D. OnBindSet
Answer: A
How do you bind a select input to an enum in Blazor?
A. By casting the enum to int
B. By using @bind and specifying the enum values
C. By calling a service in OnInitializedAsync
D. By using custom JavaScript
Answer: B
What happens if an invalid value is entered in a bound input field in Blazor?
A. The field is automatically validated
B. The field value is discarded
C. The UI does not reflect the change
D. Blazor throws a runtime error
Answer: A
How do you handle form submission with data binding in Blazor?
A. Using EditForm with OnSubmit
B. Using @bind with @onclick
C. By calling StateHasChanged()
D. By using JavaScript for form submission
Answer: A
How does Blazor handle null values in data binding?
A. It throws an exception
B. It displays nothing
C. It renders default values
D. It displays a warning
Answer: B
Which component is commonly used for forms with data binding in Blazor?
A. EditForm
B. BindForm
C. InputForm
D. FormData
Answer: A
Which binding syntax is used for one-time data binding in Blazor?
A. @bind-once
B. @bind
C. @value
D. @if
Answer: B
In Blazor, how do you bind a complex object to a form element?
A. Using @bind-value
B. Using @bind-Object
C. Using EditForm and InputX components
D. Using JSInterop
Answer: C
What is a benefit of using data binding in Blazor?
A. Simplifies UI and data synchronization
B. Increases the size of the application
C. Requires less client-side validation
D. Avoids the use of JavaScript
Answer: A
How can you disable an input field in Blazor while maintaining data binding?
A. By adding disabled attribute to the input
B. By using one-way binding
C. By overriding OnParametersSet
D. By using readonly attribute
Answer: A
How does Blazor ensure efficient rendering during data binding?
A. By using a virtual DOM
B. By optimizing component rendering
C. By caching inputs
D. By preloading components
Answer: B