Mouse button modifiers in Vue - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What happens when clicking with the middle mouse button?

Consider this Vue 3 component using mouse button modifiers:

<template>
  <button @click.middle="middleClick">Click me</button>
</template>

<script setup>
function middleClick() {
  alert('Middle button clicked!')
}
</script>

What will happen when the user clicks the button with the middle mouse button?

Vue

<template>
  <button @click.middle="middleClick">Click me</button>
</template>

<script setup>
function middleClick() {
  alert('Middle button clicked!')
}
</script>

A Nothing happens because middle clicks are ignored by Vue.

B An alert with 'Middle button clicked!' appears.

C The alert appears only if the left mouse button is clicked.

D A syntax error occurs because @click.middle is invalid.

💡 Hint

Vue supports mouse button modifiers like .middle to detect specific mouse buttons.

The .middle modifier listens for clicks from the middle mouse button. So clicking with the middle button triggers the middleClick function and shows the alert.

📝 Syntax

intermediate

Which option correctly uses the right mouse button modifier?

You want to run a method only when the right mouse button is clicked on a div. Which Vue syntax is correct?

A <div @click.right="handleRightClick">Right Click Me</div>

B <div @click.rightButton="handleRightClick">Right Click Me</div>

C <div @click.middle="handleRightClick">Right Click Me</div>

D <div @rightclick="handleRightClick">Right Click Me</div>

💡 Hint

Vue uses .right as a mouse button modifier on click events.

The correct modifier for the right mouse button on click events is .right. Other options are invalid or refer to different buttons.

🔧 Debug

advanced

Why does this middle click handler not work?

Look at this Vue 3 code snippet:

<button @click.middle.prevent="doSomething">Click</button>

The doSomething method never runs when clicking the middle mouse button. Why?

Vue

<button @click.middle.prevent="doSomething">Click</button>

A The .prevent modifier stops the event, so the handler never runs.

B The .middle modifier only works on @mousedown, not @click.

C The method name doSomething is reserved and cannot be used.

D The browser's default action for middle click (opening a new tab) prevents the event from reaching Vue.

💡 Hint

Think about what middle click usually does in browsers.

Middle clicking a link or button often triggers the browser to open a new tab. This default action can prevent Vue's click event handler from running unless you prevent the default behavior.

❓ state_output

advanced

What is the value of count after clicking left and right buttons?

Given this Vue 3 component:

<template>
  <button @click.left="increment" @click.right="decrement">Click</button>
  <p>Count: {{ count }}</p>
</template>

<script setup>
import { ref } from 'vue'
const count = ref(0)
function increment() { count.value++ }
function decrement() { count.value-- }
</script>

If the user clicks the button once with the left mouse button, then once with the right mouse button, what is the displayed count?

Vue

<template>
  <button @click.left="increment" @click.right="decrement">Click</button>
  <p>Count: {{ count }}</p>
</template>

<script setup>
import { ref } from 'vue'
const count = ref(0)
function increment() { count.value++ }
function decrement() { count.value-- }
</script>

A Count: 0

B Count: 1

C Count: -1

D Count: NaN

💡 Hint

Think about how increment and decrement affect the count starting from zero.

Clicking left increments count from 0 to 1. Clicking right decrements count from 1 back to 0. So the final count is 0.

🧠 Conceptual

expert

Which mouse button modifier does NOT exist in Vue 3?

Vue 3 supports mouse button modifiers for click events like .left, .right, and .middle. Which of these is NOT a valid Vue mouse button modifier?

A .left

B .right

C .back

D .middle

💡 Hint

Think about common mouse buttons and what Vue officially supports.

Vue 3 officially supports .left, .right, and .middle modifiers for mouse buttons. There is no .back modifier for mouse buttons in Vue.