Why templates matter in Vue - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a Vue component with a template.

Vue

<template>
  <div>{{ [1] }}</div>
</template>

<script setup>
const message = 'Hello Vue!'
</script>

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

Atext

Bmsg

Ccontent

Dmessage

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared in the script.

Forgetting to use double curly braces for interpolation.

The template uses {{ message }} to display the reactive variable message.

2fill in blank

medium

Complete the code to bind a click event in the template.

Vue

<template>
  <button @click=[1]>Click me</button>
</template>

<script setup>
function handleClick() {
  alert('Clicked!')
}
</script>

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

AhandleClick

BclickHandler

ChandleClick()

D"handleClick"

Attempts:

3 left

💡 Hint

Common Mistakes

Adding parentheses which calls the function immediately.

Using quotes which treats it as a string, not a function.

Use @click=handleClick to bind the function without calling it immediately.

3fill in blank

hard

Fix the error in the template syntax to correctly display a list.

Vue

<template>
  <ul>
    <li v-for="item in [1]" :key="item.id">{{ item.name }}</li>
  </ul>
</template>

<script setup>
const items = [
  { id: 1, name: 'Apple' },
  { id: 2, name: 'Banana' }
]
</script>

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

Alist

BitemList

Citems

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared in the script.

Adding curly braces inside the directive.

The v-for directive loops over the items array declared in the script.

4fill in blank

hard

Fill both blanks to create a reactive counter with a button.

Vue

<template>
  <div>
    <p>Count: {{ [1] }}</p>
    <button @click=[2]>Increment</button>
  </div>
</template>

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

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

Acount.value

Bincrement

Ccount

Dincrement()

Attempts:

3 left

💡 Hint

Common Mistakes

Using count.value instead of count in template.

Calling the function immediately with parentheses in the event.

Use count to display the reactive value and @click=increment to call the function on click.

5fill in blank

hard

Fill all three blanks to create a computed property and display it.

Vue

<template>
  <div>
    <p>Double: {{ [1] }}</p>
  </div>
</template>

<script setup>
import { ref, computed } from 'vue'
const number = ref(5)
const double = computed(() => [3][2]2)
</script>

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

Adouble.value

B*

C**

Dnumber.value

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * for multiplication.

Not accessing reactive refs with .value.

Displaying the computed property without .value.

Display the computed value with double.value. Use multiplication * to double number.value.

Practice

1. Why are templates important in Vue?

easy

A. They let you write HTML that updates automatically when data changes.

B. They make your JavaScript run faster.

C. They replace the need for CSS styling.

D. They allow you to write backend server code.

Solution

1. Step 1: Understand what templates do in Vue

   Templates connect HTML structure with Vue's data, so changes in data update the HTML automatically.

2. Step 2: Compare options to this understanding

   Only They let you write HTML that updates automatically when data changes. correctly describes this automatic update feature of templates.

3. Final Answer:

   They let you write HTML that updates automatically when data changes. -> Option A

4. Quick Check:

   Templates update HTML automatically [OK]

Hint: Templates link data and HTML for automatic updates [OK]

Common Mistakes:

• Thinking templates speed up JavaScript execution
• Confusing templates with CSS styling
• Believing templates handle backend code

2. Which of the following is the correct way to bind a Vue data property message inside a template?

easy

A. <div>$(message)</div>

B. <div>[message]</div>

C. <div>{ message }</div>

D. <div>{{ message }}</div>

Solution

1. Step 1: Recall Vue template syntax for data binding

   Vue uses double curly braces {{ }} to insert data values into templates.

2. Step 2: Match options to correct syntax

   Only <div>{{ message }}</div> uses the correct {{ message }} syntax for binding.

3. Final Answer:

   <div>{{ message }}</div> -> Option D

4. Quick Check:

   Vue uses {{ }} for data binding [OK]

Hint: Use double curly braces {{ }} to bind data in templates [OK]

Common Mistakes:

• Using square brackets or single braces instead of {{ }}
• Trying to use jQuery style $() syntax
• Confusing template syntax with JavaScript object notation

3. Given this Vue template and data:

<template>
  <div>Hello, {{ name }}!</div>
</template>

<script setup>
import { ref } from 'vue'
const name = ref('Alice')
</script>

What will be displayed when the component renders?

medium

A. Hello, Alice!

B. Hello, name!

C. Hello, {{ name }}!

D. Hello, undefined!

Solution

1. Step 1: Understand how Vue renders reactive data in templates

   The template uses {{ name }} which binds to the reactive variable name with value 'Alice'.

2. Step 2: Determine the rendered output

   Vue replaces {{ name }} with the current value 'Alice', so the output is 'Hello, Alice!'.

3. Final Answer:

   Hello, Alice! -> Option A

4. Quick Check:

   Reactive data shows actual value [OK]

Hint: Reactive refs show their value inside {{ }} in templates [OK]

Common Mistakes:

• Expecting the literal string '{{ name }}' to show
• Confusing variable name with its value
• Assuming undefined if not declared properly

4. What is wrong with this Vue template snippet?

<template>
  <div>{{ message }}</div>
</template>

<script setup>
const message = 'Hi there!'
</script>

medium

A. The template syntax {{ message }} is incorrect.

B. The message variable is not reactive, so template won't update if changed.

C. The script setup block is missing import of Vue.

D. The message variable should be declared inside the template.

Solution

1. Step 1: Check how data is declared for template reactivity

   The message variable is a plain string, not reactive (not a ref or reactive object).

2. Step 2: Understand template reactivity requirement

   Without reactivity, changes to message won't update the template automatically.

3. Final Answer:

   The message variable is not reactive, so template won't update if changed. -> Option B

4. Quick Check:

   Non-reactive data won't update template [OK]

Hint: Use ref() or reactive() for reactive data in templates [OK]

Common Mistakes:

• Thinking plain variables are reactive by default
• Believing template syntax {{ }} is wrong
• Assuming imports are always required in script setup

5. You want to create a Vue component that shows a list of tasks and updates automatically when tasks change. Which template approach best supports this?

hard

A. Use JavaScript to manually update the DOM elements outside the template.

B. Write tasks directly in HTML without binding to data.

C. Use a template with v-for to loop over a reactive tasks array and display each task.

D. Render tasks as a plain string inside a single <div> without looping.

Solution

1. Step 1: Identify how Vue templates handle lists reactively

   Vue uses v-for directive in templates to loop over reactive arrays and update the DOM automatically.

2. Step 2: Evaluate options for dynamic list rendering

   Only Use a template with v-for to loop over a reactive tasks array and display each task. uses v-for with reactive data, enabling automatic updates when tasks change.

3. Final Answer:

   Use a template with v-for to loop over a reactive tasks array and display each task. -> Option C

4. Quick Check:

   v-for with reactive array = dynamic list updates [OK]

Hint: Use v-for on reactive arrays to render dynamic lists [OK]

Common Mistakes:

• Hardcoding list items in HTML without data binding
• Manually manipulating DOM instead of using templates
• Rendering list as plain string without looping