How Vue differs from React and Angular - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Vue 3 component using the Composition API.

Vue

<script setup>
import { ref } from 'vue'
const count = [1](0)
</script>
<template>
  <button @click="count.value++">Count: {{ count }}</button>
</template>

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

Areactive

Bwatch

Ccomputed

Dref

Attempts:

3 left

💡 Hint

Common Mistakes

Using reactive instead of ref for primitive values.

Vue 3 uses ref to create reactive primitive values like numbers.

2fill in blank

medium

Complete the code to conditionally render a message in Vue using the new control flow directive.

Vue

<template>
  <p @if="(isLoggedIn)">Welcome back!</p>
  <p @[1]>Please log in.</p>
</template>

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

Aelse-if

Bshow

Celse

Dfor

Attempts:

3 left

💡 Hint

Common Mistakes

Using @else-if instead of @else here.

Vue 3.4+ uses @if and @else directives for control flow.

3fill in blank

hard

Fix the error in this Vue 3 component by completing the import statement correctly.

Vue

<script setup>
import { [1] } from 'vue'
const message = ref('Hello!')
</script>

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

Aref

Breactive

Ccomputed

Dwatch

Attempts:

3 left

💡 Hint

Common Mistakes

Importing reactive instead of ref for primitive values.

The ref function must be imported from 'vue' to create reactive references.

4fill in blank

hard

Fill both blanks to create a reactive object and watch its changes in Vue 3.

Vue

<script setup>
import { [1], [2] } from 'vue'
const state = [1]({ count: 0 })
watch(() => state.count, (newVal) => {
  console.log('Count changed:', newVal)
})
</script>

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

Areactive

Bref

Cwatch

Dcomputed

Attempts:

3 left

💡 Hint

Common Mistakes

Using ref instead of reactive for objects.

Not importing watch.

reactive creates a reactive object, and watch observes changes.

5fill in blank

hard

Fill the blank to create a reactive counter with a method to increment it in Vue 3 Composition API.

Vue

<script setup>
import { [1] } from 'vue'
const count = [1](0)
function increment() {
  count.value++
}
</script>
<template>
  <button @click="increment">Count: {{ count }}</button>
</template>

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

Awatch

Bref

Ccomputed

Dreactive

Attempts:

3 left

💡 Hint

Common Mistakes

Importing reactive instead of ref.

Importing unused functions.

ref creates reactive primitives. watch and computed are common imports but not used here.

Practice

1. Which of the following best describes how Vue differs from React and Angular?

easy

A. Vue uses HTML-like templates and simple reactive data, making it easier to learn.

B. Vue requires JSX for all components, unlike React and Angular.

C. Vue is a full framework with strict rules like Angular.

D. Vue does not support component-based architecture.

Solution

1. Step 1: Understand Vue's template style

   Vue uses HTML-like templates which are easy for beginners to understand, unlike React's JSX or Angular's complex templates.

2. Step 2: Compare Vue's learning curve

   Vue's simple reactive data system makes it easier to learn compared to Angular's full framework approach and React's JSX syntax.

3. Final Answer:

   Vue uses HTML-like templates and simple reactive data, making it easier to learn. -> Option A

4. Quick Check:

   Vue = Easy templates + reactive data [OK]

Hint: Vue uses HTML templates, React uses JSX, Angular is full framework [OK]

Common Mistakes:

• Confusing Vue's template syntax with React's JSX
• Thinking Vue is as complex as Angular
• Believing Vue does not use components

2. Which syntax correctly defines a Vue 3 component using the Composition API?

easy

A. export default { setup() { const count = ref(0); return { count } } }

B. @Component class MyComponent extends Vue { count = 0 }

C. function Component() { return <div>Hello</div>; }

D. export default { data() { return { count: 0 } } }

Solution

1. Step 1: Identify Vue 3 Composition API syntax

   Vue 3 uses the setup() function with ref() to create reactive state.

2. Step 2: Check options for correct usage

   export default { setup() { const count = ref(0); return { count } } } correctly uses setup() and ref(0). export default { data() { return { count: 0 } } } is Options API, function Component() { return <div>Hello</div>; } is React JSX, @Component class MyComponent extends Vue { count = 0 } is Angular/TypeScript style.

3. Final Answer:

   export default { setup() { const count = ref(0); return { count } } } -> Option A

4. Quick Check:

   Vue 3 Composition API = setup() + ref() [OK]

Hint: Vue 3 uses setup() with ref() for reactive state [OK]

Common Mistakes:

• Choosing Options API syntax for Vue 3 Composition API question
• Confusing React JSX with Vue syntax
• Using Angular decorators in Vue code

3. What will be the rendered output of this Vue template?

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

<script setup>
import { ref } from 'vue'
const message = ref('Hello Vue')
setTimeout(() => { message.value = 'Updated Vue' }, 1000)
</script>

medium

A. Error because ref() cannot be used in template

B. Updated Vue immediately

C. Hello Vue always, no change

D. Hello Vue initially, then changes to Updated Vue after 1 second

Solution

1. Step 1: Understand reactive ref and template binding

   The message is a reactive ref initialized to 'Hello Vue'. The template shows its value with {{ message }} which Vue unwraps automatically.

2. Step 2: Analyze setTimeout effect

   After 1 second, message.value changes to 'Updated Vue', so the displayed text updates reactively.

3. Final Answer:

   <div>Hello Vue</div> initially, then changes to <div>Updated Vue</div> after 1 second -> Option D

4. Quick Check:

   Reactive ref updates template text after delay [OK]

Hint: Vue ref updates template reactively after value changes [OK]

Common Mistakes:

• Thinking template shows 'message.value' literally
• Expecting no update after setTimeout
• Believing ref() cannot be used in templates

4. Identify the error in this Vue 3 component code and how to fix it:

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

<template>
  <button @click="increment">Count: {{ state.count }}</button>
</template>

medium

A. The increment function is not exposed to the template; add defineExpose({ increment }).

B. No error; code works correctly as is.

C. Reactive state should use ref() instead of reactive().

D. The @click event should be @click="increment()" with parentheses.

Solution

1. Step 1: Check function exposure in <script setup>

   In Vue 3's <script setup>, all top-level functions and variables are automatically exposed to the template.

2. Step 2: Verify reactive usage and event binding

   Using reactive() for state is correct. The event binding @click="increment" works without parentheses.

3. Final Answer:

   No error; code works correctly as is. -> Option B

4. Quick Check:

   script setup auto exposes functions [OK]

Hint: In script setup, functions auto-expose to template [OK]

Common Mistakes:

• Thinking functions need defineExpose in script setup
• Adding parentheses in @click unnecessarily
• Confusing reactive() with ref() for simple objects

5. You want to build a small interactive widget that updates a message when a button is clicked. Which Vue feature makes this simpler compared to Angular and React?

hard

A. Vue forces you to write JSX for all components like React.

B. Vue requires writing class components with decorators like Angular.

C. Vue's use of HTML-like templates with automatic reactive updates without JSX or decorators.

D. Vue does not support reactive data binding, unlike React and Angular.

Solution

1. Step 1: Understand Vue's template and reactivity advantages

   Vue uses simple HTML-like templates and reactive data that update the UI automatically without extra syntax like JSX or decorators.

2. Step 2: Compare with Angular and React

   Angular requires decorators and more setup; React uses JSX which mixes HTML and JavaScript syntax. Vue's approach is simpler for small widgets.

3. Final Answer:

   Vue's use of HTML-like templates with automatic reactive updates without JSX or decorators. -> Option C

4. Quick Check:

   Vue = simple templates + reactive updates [OK]

Hint: Vue uses simple templates and reactive data, no JSX or decorators [OK]

Common Mistakes:

• Thinking Vue requires JSX like React
• Believing Vue uses decorators like Angular
• Assuming Vue lacks reactive data binding