v-on directive for events in Vue - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to listen for a click event on the button.

Vue

<button [1]="handleClick">Click me</button>

Drag options to blanks, or click blank then click option'

Av-model:click

Bv-bind:click

Cv-on:click

Dv-if:click

Attempts:

3 left

💡 Hint

Common Mistakes

Using v-bind instead of v-on for events.

Trying to use v-model for click events.

The v-on:click directive listens for click events on the element.

2fill in blank

medium

Complete the code to use the shorthand for the click event listener.

Vue

<button [1]="submitForm">Submit</button>

Drag options to blanks, or click blank then click option'

A*click

B#click

C:click

D@click

Attempts:

3 left

💡 Hint

Common Mistakes

Using : which is for binding, not events.

Using symbols like # or * which are invalid.

The shorthand for v-on:click is @click.

3fill in blank

hard

Fix the error in the event listener syntax to correctly listen for a mouseover event.

Vue

<div [1]="showTooltip">Hover me</div>

Drag options to blanks, or click blank then click option'

Av-on:mouseover

Bv-on.mouseover

Cv-on/mouseover

Dv-on-mouseover

Attempts:

3 left

💡 Hint

Common Mistakes

Using dot notation instead of colon.

Using slashes or dashes instead of colon.

The correct syntax uses a colon: v-on:eventName.

4fill in blank

hard

Fill both blanks to listen for a keyup event and call the method with the event object.

Vue

<input [1]="handleKeyup($event)" [2]="textInput" />

Drag options to blanks, or click blank then click option'

Av-on:keyup

Bv-bind:value

Cv-model

Dv-on:click

Attempts:

3 left

💡 Hint

Common Mistakes

Using v-bind:value instead of v-model for two-way binding.

Using v-on:click instead of v-on:keyup.

v-on:keyup listens for keyup events, and v-model binds the input value.

5fill in blank

hard

Fill all three blanks to listen for a submit event, prevent default behavior, and call the submitForm method.

Vue

<form [1].prevent="submitForm" [2]="formData" [3]="formData">

Drag options to blanks, or click blank then click option'

Av-on:submit

Bv-model

Cv-bind:data

Dv-on:click

Attempts:

3 left

💡 Hint

Common Mistakes

Using v-on:click instead of v-on:submit.

Forgetting the .prevent modifier.

Using v-bind:data incorrectly.

v-on:submit.prevent listens for submit and prevents default. v-model binds form data, and v-bind:data binds data attribute.

Practice

1. What does the v-on directive do in Vue?

easy

A. It fetches data from a server automatically.

B. It listens for user events and runs code when they happen.

C. It styles HTML elements dynamically.

D. It creates new Vue components.

Solution

1. Step 1: Understand the purpose of v-on

   v-on is used to listen to user actions like clicks or key presses.

2. Step 2: Identify what happens when an event is detected

   When the event occurs, v-on runs the specified code or method.

3. Final Answer:

   It listens for user events and runs code when they happen. -> Option B

4. Quick Check:

   Event listening = C [OK]

Hint: Remember: v-on = listen and react to events [OK]

Common Mistakes:

• Confusing v-on with styling directives
• Thinking v-on fetches data automatically
• Assuming v-on creates components

2. Which of the following is the correct syntax to listen for a click event on a button using v-on?

easy

A. Click me

B. Click me

C. Click me

D. Click me

Solution

1. Step 1: Check the correct v-on syntax

   The correct syntax uses a colon after v-on followed by the event name, like v-on:click.

2. Step 2: Verify the event handler format

   The handler should be a method name without parentheses in the directive, so handleClick is correct.

3. Final Answer:

   <button v-on:click="handleClick">Click me</button> -> Option A

4. Quick Check:

   Correct syntax = B [OK]

Hint: Use v-on:event="handler" with colon, no parentheses [OK]

Common Mistakes:

• Using v-on-click instead of v-on:click
• Adding parentheses in the handler inside directive
• Using @click with parentheses (valid but different from v-on syntax)

3. What will happen when the button is clicked in this Vue template?

<button v-on:click="count++">Clicked {{ count }} times</button>
<script setup>
import { ref } from 'vue'
const count = ref(0)
</script>

medium

A. The count will reset to 0 every time the button is clicked.

B. The count will stay at 0 and never change.

C. The button will cause an error because count is not a number.

D. The count will increase by 1 each time the button is clicked and update the displayed number.

Solution

1. Step 1: Understand the reactive variable count

   count is a reactive reference starting at 0, so changes update the UI automatically.

2. Step 2: Analyze the click event handler

   Each click runs count++, increasing the value by 1 and updating the displayed text.

3. Final Answer:

   The count will increase by 1 each time the button is clicked and update the displayed number. -> Option D

4. Quick Check:

   Reactive ref increments = D [OK]

Hint: Reactive refs update UI when changed inside v-on [OK]

Common Mistakes:

• Thinking count is a plain variable, not reactive
• Assuming count resets on each click
• Believing the code causes an error

4. Identify the error in this Vue template:

<button v-on:click="submitForm()">Submit</button>
<script setup>
function submitForm {
  alert('Form submitted')
}
</script>

medium

A. The function declaration is missing parentheses after the name.

B. The event handler should not have parentheses in the template.

C. The alert function is not allowed inside Vue methods.

D. The v-on directive should be written as @click instead.

Solution

1. Step 1: Check the function declaration syntax

   The function submitForm is declared without parentheses, which is invalid syntax in JavaScript.

2. Step 2: Confirm the correct function syntax

   It should be function submitForm() { ... } with parentheses after the name.

3. Final Answer:

   The function declaration is missing parentheses after the name. -> Option A

4. Quick Check:

   Function syntax error = A [OK]

Hint: Always add () after function names in declarations [OK]

Common Mistakes:

• Removing parentheses in function declarations
• Thinking parentheses are wrong in event handlers
• Confusing directive syntax with error cause

5. You want to listen for a key press event on an input using v-on and run a method only when the Enter key is pressed. Which is the correct way to do this in Vue?

hard

A.

B.

C.

D.

Solution

1. Step 1: Understand Vue event modifiers

   Vue supports event modifiers like .enter to listen only for Enter key presses.

2. Step 2: Check the correct syntax for key modifiers

   v-on:keyup.enter="submit()" listens for keyup events only when Enter is pressed and runs submit().

3. Final Answer:

   <input v-on:keyup.enter="submit()" /> -> Option C

4. Quick Check:

   Use .enter modifier for Enter key events = A [OK]

Hint: Use .enter modifier with v-on for Enter key events [OK]

Common Mistakes:

• Trying to check event.key manually inside template
• Using key attribute instead of event modifier
• Forgetting parentheses in method call