Vue.js MCQs with answers

What is the purpose of the v-show directive in Vue.js?

• A. Toggles the visibility of an element based on a condition
• B. Displays an element conditionally
• C. Binds a class dynamically
• D. Creates a sliding transition effect

Answer: A. Toggles the visibility of an element based on a condition

In Vue.js, what is the purpose of the nextTick function?

• A. Delays the execution of a function until the next event loop cycle
• B. Forces an immediate re-render of the component
• C. Allows for asynchronous execution of methods
• D. Initializes the component before it is mounted

Answer: A. Delays the execution of a function until the next event loop cycle

How can you dynamically bind styles to an element based on a condition in Vue.js?

• A. Using v-style
• B. Using v-bind with a style object
• C. Using v-class
• D. Using v-if with inline styles

Answer: B. Using v-bind with a style object

What is the role of the .number modifier in Vue.js when using v-model?

• A. Converts the input value to a string
• B. Forces the input to accept only numeric values
• C. Converts the input value to a number
• D. Rounds the input value to the nearest integer

Answer: C. Converts the input value to a number

What is the purpose of the .prevent modifier in Vue.js when handling form submissions?

• A. Stops the default form submission behavior
• B. Delays the form submission until a later event
• C. Forces the form to submit immediately
• D. Prevents the form from being reset

Answer: A. Stops the default form submission behavior

How does Vue.js handle animations and transitions?

• A. Using the v-animate directive
• B. Using CSS classes and the transition component
• C. Using the v-transition directive
• D. Automatically with no need for additional configuration

Answer: B. Using CSS classes and the transition component

What is the purpose of the v-pre directive in Vue.js?

• A. Exempts an element from being compiled
• B. Skips compilation for the element and its children
• C. Marks an element as private
• D. Prevents an element from being displayed

Answer: B. Skips compilation for the element and its children

How can you prevent a Vue.js component from being rendered until its data is ready?

• A. Using the v-show directive
• B. Using the v-if directive
• C. Using the beforeMount lifecycle hook
• D. Using the v-pre directive

Answer: B. Using the v-if directive

What is the significance of the v-slot directive in Vue.js?

• A. Defines a custom directive
• B. Marks a slot as required
• C. Specifies the position of a slot in the template
• D. Used for named slots in component composition

Answer: D. Used for named slots in component composition

In Vue.js, what is the purpose of the computed property?

• A. Stores data that can be modified by the user
• B. Performs asynchronous operations
• C. Calculates derived data based on reactive data
• D. Manages the state of a component

Answer: C. Calculates derived data based on reactive data

How can you define a method in Vue.js that executes when a button is clicked?

• A. Using the v-on:click directive
• B. Using the @click shorthand
• C. Both A and B
• D. Using the v-bind:click directive

Answer: C. Both A and B

What is the purpose of the v-if and v-else directives in Vue.js?

• A. Used for conditional rendering
• B. Defines custom directives
• C. Handles form submissions
• D. Adds or removes CSS classes

Answer: A. Used for conditional rendering

What does the key attribute do when used with v-for in Vue.js?

• A. Specifies the type of transition effect
• B. Provides a unique identifier for elements in a list
• C. Sets the initial value for data properties
• D. Adds a custom attribute to each element in a list

Answer: B. Provides a unique identifier for elements in a list

How can you include external libraries like Axios in a Vue.js project?

• A. Download and manually include the library in the project
• B. Import the library using the import statement
• C. Use a CDN link in the HTML file
• D. All of the above

Answer: B. Import the library using the import statement

What is the purpose of the v-bind directive in Vue.js?

• A. Binds an attribute to an expression
• B. Binds a class dynamically
• C. Binds an event handler
• D. Binds a style dynamically

Answer: A. Binds an attribute to an expression

What is the main role of Vuex in a Vue.js application?

• A. Manages global state
• B. Handles routing
• C. Facilitates component communication
• D. Provides a way to define mixins

Answer: A. Manages global state

What is the primary purpose of the v-model directive in Vue.js?

• A. Binds an input element to a variable
• B. Handles form submissions
• C. Defines a model for a component
• D. Enables two-way data binding on form elements

Answer: D. Enables two-way data binding on form elements

How can you dynamically switch between multiple components in Vue.js?

• A. Using the v-if directive
• B. Using the v-switch directive
• C. Using the v-bind directive
• D. Using dynamic components with the :is attribute

Answer: D. Using dynamic components with the :is attribute

What is the purpose of the v-on directive in Vue.js?

• A. Binds an attribute to an expression
• B. Binds a class dynamically
• C. Binds an event handler
• D. Binds a style dynamically

Answer: C. Binds an event handler

Which directive is used for dynamic component creation in Vue.js?

• A. v-if
• B. v-switch
• C. v-bind
• D. v-on

Answer: C. v-bind

In Vue.js, what is the purpose of the beforeDestroy lifecycle hook?

• A. Executed before a component is created
• B. Invoked before a component is destroyed
• C. Called before a component is mounted to the DOM
• D. Executed when a component is updated

Answer: B. Invoked before a component is destroyed

What is the role of the transition component in Vue.js?

• A. Manages transitions and animations for elements entering or leaving the DOM
• B. Defines a custom directive
• C. Controls the state of a component
• D. Facilitates communication between parent and child components

Answer: A. Manages transitions and animations for elements entering or leaving the DOM

What is the purpose of the .sync modifier in Vue.js when using props?

• A. Enables two-way data binding between parent and child components
• B. Forces synchronous rendering of components
• C. Synchronizes data with a server
• D. Prevents unnecessary re-renders

Answer: A. Enables two-way data binding between parent and child components

How can you handle asynchronous operations in Vue.js?

• A. Using the async keyword in methods
• B. Utilizing the await keyword within lifecycle hooks
• C. Using promises or async/await syntax
• D. Both B and C

Answer: C. Using promises or async/await syntax

What is the purpose of the .trim modifier in Vue.js when using v-model?

• A. Trims leading and trailing whitespace from the input value
• B. Converts the input value to lowercase
• C. Removes all whitespace from the input value
• D. Prevents user input from being trimmed

Answer: A. Trims leading and trailing whitespace from the input value

In Vue.js, what is the significance of the mixins option?

• A. Used for mixing colors in the application
• B. Enables the use of multiple CSS mixins
• C. Provides a way to reuse and share component options
• D. Facilitates communication between sibling components

Answer: C. Provides a way to reuse and share component options

What is the purpose of the .once modifier in Vue.js event handling?

• A. Listens to the event only once
• B. Prevents the default browser behavior
• C. Adds a one-time delay to the event handler
• D. Allows the event to propagate only once

Answer: A. Listens to the event only once

How does Vue.js handle reactivity in its data system?

• A. By using a reactive programming paradigm
• B. By implementing a virtual DOM
• C. Through getter and setter functions
• D. By using traditional event listeners

Answer: C. Through getter and setter functions

What is the purpose of the template option in a Vue.js component?

• A. Defines the structure of the component's HTML
• B. Specifies the CSS styles for the component
• C. Configures the component's state
• D. Declares the data properties for the component

Answer: A. Defines the structure of the component's HTML

What is the main advantage of using Single File Components in Vue.js?

• A. Improved SEO
• B. Simplified project structure
• C. Enhanced security
• D. Better performance

Answer: B. Simplified project structure

What does the .lazy modifier do when used with the v-bind directive in Vue.js?

• A. Defers the binding until a later event
• B. Delays the rendering of an element
• C. Lazily loads the binding data
• D. Forces immediate binding

Answer: C. Lazily loads the binding data

In Vue.js, how can you dynamically bind a CSS class based on a condition?

• A. Using v-bind:class
• B. Using v-class
• C. Using v-style
• D. Using v-if

Answer: A. Using v-bind:class

What is the purpose of the v-pre directive in Vue.js?

• A. Prevents a directive from being compiled
• B. Skips compilation for the element and its children
• C. Prevents a component from rendering
• D. Allows using raw HTML in an element

Answer: B. Skips compilation for the element and its children

How can you handle errors in a Vue.js application?

• A. Using try...catch blocks in the template
• B. Utilizing the error lifecycle hook
• C. Implementing a global error handler
• D. Both B and C

Answer: D. Both B and C

What is the purpose of the ref attribute in Vue.js?

• A. Represents a reference to a component's data
• B. Provides a way to reference an element or component in the template
• C. Specifies the routing configuration for a component
• D. Defines the relationship between parent and child components

Answer: B. Provides a way to reference an element or component in the template

In Vue.js, what is the purpose of the .once modifier when binding an event?

• A. Delays the execution of the event handler
• B. Stops the event propagation to parent elements
• C. Binds the event listener only once
• D. Prevents the default browser behavior

Answer: C. Binds the event listener only once

How can you perform unit testing in Vue.js components?

• A. Using the vue-test-utils library with Jest or Mocha
• B. Utilizing the v-test directive
• C. Using the vue-testing-library with Karma
• D. Both A and C

Answer: A. Using the vue-test-utils library with Jest or Mocha

What is the purpose of the .exact modifier in Vue Router?

• A. Matches the route exactly without considering nested routes
• B. Executes the route handler exactly once
• C. Forces an exact match for dynamic route segments
• D. Allows case-sensitive matching for routes

Answer: A. Matches the route exactly without considering nested routes

What does the v-once directive do in Vue.js?

• A. Renders the element and its children only once
• B. Binds an event listener that fires only once
• C. Executes the event handler only once
• D. Applies a one-time data binding to an element

Answer: A. Renders the element and its children only once

In Vue.js, what does the $refs property allow you to access?

• A. Parent component data
• B. Child component data
• C. DOM elements or child components
• D. Vuex store state

Answer: C. DOM elements or child components

What is the purpose of the v-pre directive in Vue.js?

• A. Skips compilation for the element and its children
• B. Prevents a component from rendering
• C. Allows using raw HTML in an element
• D. Prevents a directive from being compiled

Answer: A. Skips compilation for the element and its children

How can you conditionally render content based on whether a property exists in Vue.js?

• A. Using v-if with a condition checking for property existence
• B. Using v-show with a condition checking for property existence
• C. Using v-bind with a condition checking for property existence
• D. Using v-switch with a condition checking for property existence

Answer: A. Using v-if with a condition checking for property existence

What is the purpose of the extends option in a Vue.js component?

• A. Extends the lifecycle of the component
• B. Inheritance of data properties from a parent component
• C. Allows components to extend each other
• D. It is not a valid option in Vue.js components

Answer: B. Inheritance of data properties from a parent component

How do you handle asynchronous operations in Vue.js components?

• A. Using async and await in the mounted lifecycle hook
• B. Using Promises in the created and mounted lifecycle hooks
• C. Handling asynchronous operations directly in the template
• D. Using the asyncData hook provided by Nuxt.js

Answer: B. Using Promises in the created and mounted lifecycle hooks

Which directive is used to bind an attribute conditionally in Vue.js?

• A. v-attribute
• B. v-bind
• C. v-condition
• D. v-attr

Answer: B. v-bind

What is the purpose of the .capture modifier in Vue.js event handling?

• A. Captures the event and prevents it from reaching the target
• B. Delays the execution of the event handler
• C. Stops the event propagation to parent elements
• D. Adds a debounce to the event

Answer: A. Captures the event and prevents it from reaching the target

In Vue.js, what is the significance of the nextTick method?

• A. Delays the execution of a function until the next tick of the event loop
• B. Executes a function immediately
• C. Used for transitioning between different routes
• D. Updates the DOM in real-time

Answer: A. Delays the execution of a function until the next tick of the event loop

What is the purpose of the v-html directive in Vue.js?

• A. Binds an attribute to a variable
• B. Inserts raw HTML content into an element
• C. Conditionally shows or hides an element
• D. Binds a class dynamically

Answer: B. Inserts raw HTML content into an element

How do you define a custom event in a child component and listen for it in a parent component in Vue.js?

• A. Using the v-on directive in the parent and $emit in the child
• B. Using the v-emit directive in the parent and $on in the child
• C. Using the v-model directive in the parent and $emit in the child
• D. Using the v-bind directive in the parent and $emit in the child

Answer: A. Using the v-on directive in the parent and $emit in the child

What is the purpose of the .once modifier in Vue.js event handling?

• A. Stops the event propagation to parent elements
• B. Executes the event handler only once
• C. Prevents the default browser behavior
• D. Delays the execution of the event handler

Answer: B. Executes the event handler only once

Which Vue.js lifecycle hook is called when a component is inserted into the DOM?

• A. beforeCreate
• B. created
• C. beforeMount
• D. mounted

Answer: D. mounted

What is the purpose of the .prevent modifier in Vue.js event handling?

• A. Stops the event propagation to parent elements
• B. Prevents the default browser behavior
• C. Delays the execution of the event handler
• D. Adds a debounce to the event

Answer: B. Prevents the default browser behavior

How do you dynamically bind a class to an element in Vue.js based on a condition?

• A. Using v-if with a condition checking for class existence
• B. Using v-bind with a condition checking for class existence
• C. Using v-switch with a condition checking for class existence
• D. Using v-class with a condition checking for class existence

Answer: B. Using v-bind with a condition checking for class existence