v-else and v-else-if in Vue - Mini Project: Build & Apply

Using v-else and v-else-if in Vue 3

📖 Scenario: You are building a simple Vue 3 app that shows a message based on the current weather condition.

🎯 Goal: Create a Vue 3 component that uses v-if, v-else-if, and v-else directives to display different messages for weather conditions.

📋 What You'll Learn

Create a reactive variable called weather with the value 'sunny'.

Create a reactive variable called temperature with the value 25.

Use v-if to show 'It is sunny and warm!' when weather is 'sunny' and temperature is above 20.

Use v-else-if to show 'It is rainy today.' when weather is 'rainy'.

Use v-else to show 'Weather is unknown.' for all other cases.

💡 Why This Matters

🌍 Real World

Conditional rendering is common in web apps to show different content based on user data or app state, like showing different messages for weather or user status.

💼 Career

Understanding <code>v-if</code>, <code>v-else-if</code>, and <code>v-else</code> is essential for Vue developers to build dynamic and interactive user interfaces.

1

Set up the Vue component with reactive data

Create a Vue 3 component using <script setup>. Inside it, create a reactive variable called weather with the value 'sunny' and another reactive variable called temperature with the value 25.

Vue

  



// Create reactive variables weather and temperature
// Your code here

Hint

Use ref from Vue to create reactive variables.

2

Add the v-if condition for sunny and warm weather

Inside the <template>, add a <p> tag that uses v-if to show the text 'It is sunny and warm!' only when weather is 'sunny' and temperature is greater than 20.

Vue

  
  



import { ref } from 'vue'

const weather = ref('sunny')
const temperature = ref(25)

Hint

Use v-if with a condition combining weather and temperature.

3

Add the v-else-if condition for rainy weather

Below the v-if paragraph, add another <p> tag that uses v-else-if to show the text 'It is rainy today.' only when weather is 'rainy'.

Vue

   20">It is sunny and warm!
  
  



import { ref } from 'vue'

const weather = ref('sunny')
const temperature = ref(25)

Hint

Use v-else-if with a condition checking if weather equals 'rainy'.

4

Add the v-else condition for unknown weather

Add a final <p> tag below the others that uses v-else to show the text 'Weather is unknown.' for all other cases.

Vue

   20">It is sunny and warm!
  It is rainy today.
  
  



import { ref } from 'vue'

const weather = ref('sunny')
const temperature = ref(25)

Hint

Use v-else without a condition to catch all other cases.

Practice

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

easy

A. Runs only if the first v-if condition is true

B. Runs when all previous v-if and v-else-if conditions are false

C. Runs independently of any other condition

D. Runs only if the last v-else-if condition is true

Solution

1. Step 1: Understand v-if and v-else-if behavior

   v-if runs if its condition is true; v-else-if runs if the previous v-if or v-else-if was false and its own condition is true.

2. Step 2: Understand v-else behavior

   v-else runs only if all previous v-if and v-else-if conditions are false, acting as a fallback.

3. Final Answer:

   Runs when all previous v-if and v-else-if conditions are false -> Option B

4. Quick Check:

   v-else = fallback [OK]

Hint: Remember: v-else is the fallback after all conditions fail [OK]

Common Mistakes:

• Thinking v-else runs independently
• Confusing v-else with v-else-if
• Assuming v-else requires a condition

2. Which of the following is the correct syntax for using v-else-if in Vue?

easy

A. <div v-else-if="condition">Content</div>

B. <div v-else-if>condition</div>

C. <div v-else-if:condition>Content</div>

D. <div v-else-if(condition)>Content</div>

Solution

1. Step 1: Recall Vue directive syntax

   Vue directives use the format v-directive="expression" to bind conditions or values.

2. Step 2: Check each option's syntax

   <div v-else-if="condition">Content</div> uses v-else-if="condition", which is correct. Options B, C, and D use invalid syntax forms.

3. Final Answer:

   <div v-else-if="condition">Content</div> -> Option A

4. Quick Check:

   Directive syntax = v-else-if="condition" [OK]

Hint: Use quotes for conditions in v-else-if [OK]

Common Mistakes:

• Omitting quotes around condition
• Using parentheses or colons incorrectly
• Writing v-else-if without a condition

3. Given this Vue template snippet:

<div v-if="score >= 90">A</div>
<div v-else-if="score >= 75">B</div>
<div v-else-if="score >= 60">C</div>
<div v-else>F</div>

What will be displayed if score is 80?

medium

A. A

B. C

C. B

D. F

Solution

1. Step 1: Evaluate the first condition score >= 90

   Since 80 is less than 90, this condition is false, so this block does not render.

2. Step 2: Evaluate the second condition score >= 75

   80 is greater than or equal to 75, so this condition is true. Vue renders this block and skips the rest.

3. Final Answer:

   B -> Option C

4. Quick Check:

   80 >= 75 = true, so output is B [OK]

Hint: Check conditions top to bottom; first true runs [OK]

Common Mistakes:

• Choosing the first condition without checking value
• Ignoring order of v-else-if blocks
• Assuming multiple blocks render

4. What is wrong with this Vue template?

<div v-if="isActive">Active</div>
<div v-else-if>Inactive</div>
<div v-else>Unknown</div>

medium

A. The v-else-if directive is missing a condition

B. The v-else directive cannot be used after v-else-if

C. The v-if directive must have a closing tag

D. There should be no v-else after v-if

Solution

1. Step 1: Check v-else-if usage

   v-else-if requires a condition to evaluate. Here, it is used without any condition, which is invalid syntax.

2. Step 2: Verify other directives

   v-else can follow v-else-if, and v-if has proper closing tags, so no issues there.

3. Final Answer:

   The v-else-if directive is missing a condition -> Option A

4. Quick Check:

   v-else-if needs a condition [OK]

Hint: v-else-if always needs a condition in quotes [OK]

Common Mistakes:

• Leaving v-else-if without condition
• Thinking v-else can't follow v-else-if
• Confusing v-if closing tags

5. You want to display a message based on a user's status using Vue directives. The statuses are: 'admin', 'editor', and others. Which template correctly uses v-if, v-else-if, and v-else to show 'Admin Access', 'Editor Access', or 'Guest Access' respectively?

hard

A. <div v-if="status === 'admin'">Admin Access</div>
<div v-else>Editor Access</div>
<div v-else-if="status === 'editor'">Guest Access</div>

B. <div v-if="status === 'admin'">Admin Access</div>
<div v-if="status === 'editor'">Editor Access</div>
<div v-else>Guest Access</div>

C. <div v-if="status === 'admin'">Admin Access</div>
<div v-else-if>Editor Access</div>
<div v-else>Guest Access</div>

D. <div v-if="status === 'admin'">Admin Access</div>
<div v-else-if="status === 'editor'">Editor Access</div>
<div v-else>Guest Access</div>

Solution

1. Step 1: Check the chaining of conditions

   <div v-if="status === 'admin'">Admin Access</div>
   <div v-else-if="status === 'editor'">Editor Access</div>
   <div v-else>Guest Access</div>

   correctly uses v-if, then v-else-if with a condition, then v-else as fallback.

2. Step 2: Verify other options for errors

   <div v-if="status === 'admin'">Admin Access</div>
   <div v-if="status === 'editor'">Editor Access</div>
   <div v-else>Guest Access</div>

   uses two v-if directives, which are independent and can cause multiple blocks to render.

   <div v-if="status === 'admin'">Admin Access</div>
   <div v-else-if>Editor Access</div>
   <div v-else>Guest Access</div>

   uses v-else-if without a condition, which is invalid.

   <div v-if="status === 'admin'">Admin Access</div>
   <div v-else>Editor Access</div>
   <div v-else-if="status === 'editor'">Guest Access</div>

   places v-else before v-else-if, which breaks the chain.

3. Final Answer:

   The template that correctly chains v-if, v-else-if with condition, and v-else -> Option D

4. Quick Check:

   v-if, v-else-if with condition, then v-else [OK]

Hint: Chain conditions: v-if, v-else-if with condition, then v-else [OK]

Common Mistakes:

• Using multiple v-if instead of v-else-if
• Omitting condition in v-else-if
• Placing v-else before v-else-if