Lazy loading routes in Vue - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Home component lazily.

Vue

const Home = () => import([1]);

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

A'./components/Home.vue'

B'Home.vue'

C'./Home.vue'

D'components/Home.vue'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the './' at the start of the path.

Using just the file name without path.

Omitting the file extension.

Lazy loading in Vue routes uses dynamic import with the relative path to the component file.

2fill in blank

medium

Complete the code to define a lazy loaded route for About component.

Vue

const routes = [{ path: '/about', component: [1] }];

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

A'./components/About.vue'

BAbout

C() => import('./components/About.vue')

Dimport('./components/About.vue')

Attempts:

3 left

💡 Hint

Common Mistakes

Using import without wrapping in a function.

Passing a string path instead of a function.

Using a component variable without lazy loading.

Lazy loaded routes use a function returning an import promise for the component.

3fill in blank

hard

Fix the error in the lazy loading syntax for the Contact component.

Vue

const Contact = [1];

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

A'./components/Contact.vue'

B'./Contact.vue'

C'Contact.vue'

D() => import('./components/Contact.vue')

Attempts:

3 left

💡 Hint

Common Mistakes

Calling import directly without a function.

Using incorrect path strings.

Missing arrow function syntax.

Lazy loading requires a function returning the import promise, not direct import call.

4fill in blank

hard

Fill both blanks to create a lazy loaded route with name 'Profile' and path '/profile'.

Vue

const routes = [{ path: [1], name: [2], component: () => import('./components/Profile.vue') }];

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

A'/profile'

B'Profile'

C'profile'

D'/Profile'

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting quotes around path or name.

Using wrong case or missing slash in path.

Confusing path and name values.

The path should be '/profile' as a string and the route name 'Profile' as a string.

5fill in blank

hard

Fill all three blanks to create a lazy loaded route with path '/dashboard', name 'Dashboard', and component imported from './views/Dashboard.vue'.

Vue

const routes = [{ path: [1], name: [2], component: () => import([3]) }];

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

A'/dashboard'

B'Dashboard'

C'./views/Dashboard.vue'

D'dashboard'

Attempts:

3 left

💡 Hint

Common Mistakes

Missing quotes around strings.

Using incorrect path or name casing.

Forgetting the './' in import path.

Use the exact path string '/dashboard', name 'Dashboard', and import path './views/Dashboard.vue'.

Practice

1. What is the main benefit of using lazy loading for routes in Vue?

easy

A. It automatically caches all components in the browser.

B. It preloads all components at app start for faster navigation.

C. It loads components only when the route is visited, reducing initial load time.

D. It disables routing and shows all components on one page.

Solution

1. Step 1: Understand lazy loading concept

   Lazy loading means loading something only when it is needed, not before.

2. Step 2: Apply to Vue routes

   In Vue, lazy loading routes means components load only when their route is visited, reducing initial app size and speeding start time.

3. Final Answer:

   It loads components only when the route is visited, reducing initial load time. -> Option C

4. Quick Check:

   Lazy loading = load on demand [OK]

Hint: Lazy loading means load components only when needed [OK]

Common Mistakes:

• Thinking lazy loading preloads all components
• Confusing lazy loading with caching
• Believing lazy loading disables routing

2. Which of the following is the correct syntax to lazy load a route component in Vue Router?

easy

A. component: import('./MyComponent.vue')

B. component: './MyComponent.vue'

C. component: () => require('./MyComponent.vue')

D. component: () => import('./MyComponent.vue')

Solution

1. Step 1: Recall Vue Router lazy loading syntax

   Vue Router uses dynamic import with arrow function: () => import('path').

2. Step 2: Check each option

   component: () => import('./MyComponent.vue') matches correct syntax. component: import('./MyComponent.vue') misses arrow function. component: () => require('./MyComponent.vue') uses require which is not standard for lazy loading in Vue 3. component: './MyComponent.vue' is just a string, not a function.

3. Final Answer:

   component: () => import('./MyComponent.vue') -> Option D

4. Quick Check:

   Lazy load syntax = arrow function + import() [OK]

Hint: Lazy load uses arrow function returning import() [OK]

Common Mistakes:

• Omitting arrow function
• Using require() instead of import()
• Assigning component to string path directly

3. Given this Vue Router route config, what will happen when the user visits '/dashboard' for the first time?

const routes = [
  {
    path: '/dashboard',
    component: () => import('./Dashboard.vue')
  }
]

medium

A. The Dashboard component is loaded immediately when the app starts.

B. The Dashboard component is loaded only when the '/dashboard' route is visited.

C. The Dashboard component is never loaded.

D. The Dashboard component is loaded twice.

Solution

1. Step 1: Analyze the route config

   The component is assigned as a function returning import(), which means lazy loading.

2. Step 2: Understand lazy loading behavior

   The component will load only when the route '/dashboard' is visited, not before.

3. Final Answer:

   The Dashboard component is loaded only when the '/dashboard' route is visited. -> Option B

4. Quick Check:

   Lazy load means load on visit [OK]

Hint: Lazy loaded components load on route visit, not app start [OK]

Common Mistakes:

• Assuming component loads at app start
• Thinking component never loads
• Believing component loads multiple times automatically

4. Identify the error in this Vue Router lazy loading route config:

const routes = [
  {
    path: '/profile',
    component: import('./Profile.vue')
  }
]

medium

A. Missing arrow function wrapping the import call.

B. The path should be '/profiles' instead of '/profile'.

C. The import path must be absolute, not relative.

D. Lazy loading is not supported in Vue Router.

Solution

1. Step 1: Check lazy loading syntax

   Lazy loading requires component to be a function returning import(), like () => import('...').

2. Step 2: Identify the error

   Here, import() is called directly without arrow function, causing immediate import and syntax error.

3. Final Answer:

   Missing arrow function wrapping the import call. -> Option A

4. Quick Check:

   Lazy load needs () => import() [OK]

Hint: Lazy load must use arrow function wrapping import() [OK]

Common Mistakes:

• Calling import() directly without arrow function
• Changing path unnecessarily
• Believing lazy loading is unsupported

5. You want to lazy load two nested routes in Vue Router: '/settings' and '/settings/profile'. Which is the correct way to configure lazy loading for both routes?

hard

A. Use component: () => import() for both routes inside children array.

B. Lazy load only the parent route; child routes load immediately.

C. Use static imports for both routes to avoid delays.

D. Define child routes outside the parent route config.

Solution

1. Step 1: Understand nested route lazy loading

   Each route can lazy load its component independently using () => import().

2. Step 2: Apply to nested routes

   Both '/settings' and '/settings/profile' should have component properties with arrow functions returning import() to lazy load separately.

3. Step 3: Check other options

   Lazy load only the parent route; child routes load immediately. is wrong because child routes won't lazy load automatically. Use static imports for both routes to avoid delays. disables lazy loading. Define child routes outside the parent route config. is unrelated to lazy loading.

4. Final Answer:

   Use component: () => import() for both routes inside children array. -> Option A

5. Quick Check:

   Lazy load each nested route with () => import() [OK]

Hint: Lazy load each nested route with arrow function import() [OK]

Common Mistakes:

• Lazy loading only parent route
• Using static imports for lazy loading
• Separating child routes incorrectly