Nested routes and child views in Vue - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What will be rendered by this nested route setup?

Given the Vue Router configuration below, what will the user see when navigating to /dashboard/settings?

Vue

const routes = [
  {
    path: '/dashboard',
    component: DashboardLayout,
    children: [
      { path: '', component: DashboardHome },
      { path: 'settings', component: DashboardSettings }
    ]
  }
];

A Only the DashboardSettings component content is shown.

B Only DashboardLayout content is shown, no child components render.

C DashboardLayout wraps DashboardSettings content, showing both layouts and settings content.

D DashboardHome content is shown instead of DashboardSettings.

💡 Hint

Think about how parent and child components render together in nested routes.

In Vue Router, the parent component (DashboardLayout) renders and inside it the child route component (DashboardSettings) is displayed where <router-view> is placed. So both appear.

📝 Syntax

intermediate

Identify the syntax error in this nested route definition

Which option contains the correct syntax for defining nested routes in Vue Router?

Vue

const routes = [
  {
    path: '/profile',
    component: ProfileLayout,
    children: [
      { path: 'info', component: ProfileInfo },
      { path: 'settings', component: ProfileSettings }
    ]
  }
];

A children: { path: 'info', component: ProfileInfo }

B children: [ { path: 'info', component: ProfileInfo } ]

C children: [ { path: '/info', component: ProfileInfo } ]

D children: [ { path: '', component: ProfileInfo } ]

💡 Hint

Remember child paths should be relative, not absolute.

Child routes must have relative paths without a leading slash. Option B correctly uses 'info' as the path.

❓ state_output

advanced

What is the rendered output when navigating to a nested route with multiple ?

Consider a parent route with two nested child routes rendered in separate <router-view> elements. What will be displayed when navigating to /app/dashboard/overview?

Vue

const routes = [
  {
    path: '/app',
    component: AppLayout,
    children: [
      {
        path: 'dashboard',
        components: {
          default: DashboardMain,
          sidebar: DashboardSidebar
        },
        children: [
          { path: 'overview', component: DashboardOverview }
        ]
      }
    ]
  }
];

A AppLayout renders DashboardMain and DashboardSidebar, and DashboardOverview replaces DashboardMain.

B DashboardSidebar is not rendered because it is not a child route.

C Only DashboardOverview is rendered, others are replaced.

D AppLayout renders DashboardMain and DashboardSidebar, and DashboardOverview renders inside DashboardMain's <router-view>.

💡 Hint

Think about named views and nested child routes inside components.

Named views render DashboardMain and DashboardSidebar inside AppLayout. DashboardOverview renders inside DashboardMain's because it is a child route of dashboard.

🔧 Debug

advanced

Why does the child route component not render inside the parent?

Given this route setup, the child component ChildView does not appear when navigating to /parent/child. What is the most likely cause?

Vue

const routes = [
  {
    path: '/parent',
    component: ParentView,
    children: [
      { path: 'child', component: ChildView }
    ]
  }
];

// ParentView.vue template:
// <template><div>Parent Content</div></template>

A ParentView component is missing a <router-view> to display child routes.

B ChildView path should start with a slash '/child' to render correctly.

C The routes array must be flat; nested children are not supported.

D ChildView component must be imported inside ParentView component.

💡 Hint

Check how child routes render inside parent components.

For child routes to render, the parent component must include a element where the child component will appear.

🧠 Conceptual

expert

How does Vue Router handle nested route matching order?

When multiple nested routes match a URL, how does Vue Router decide which components to render?

A Vue Router renders all matched nested routes from parent to deepest child in order.

B Vue Router renders only the deepest matched child route component, ignoring parents.

C Vue Router renders only the first matched route at the top level, ignoring children.

D Vue Router randomly picks one matched route component to render.

💡 Hint

Think about how nested routes build up the page layout.

Vue Router renders matched routes hierarchically: parent components render first, then child components inside their , building the full nested UI.

Practice

1. What is the main purpose of nested routes in Vue Router?

easy

A. To load multiple Vue apps on the same page

B. To display child views inside a parent view using <router-view />

C. To create routes without components

D. To disable navigation guards

Solution

1. Step 1: Understand nested routes concept

   Nested routes allow smaller views (child views) to be shown inside bigger views (parent views).

2. Step 2: Identify how child views are displayed

   Child views appear inside the parent component where <router-view /> is placed.

3. Final Answer:

   To display child views inside a parent view using <router-view /> -> Option B

4. Quick Check:

   Nested routes = child views inside parent with <router-view /> [OK]

Hint: Nested routes show child views inside parents with [OK]

Common Mistakes:

• Thinking nested routes load separate apps
• Believing nested routes don't need
• Confusing nested routes with route guards

2. Which of the following is the correct way to define a child route inside a parent route in Vue Router?

easy

A. { path: '/parent', component: Parent, children: [{ path: 'child', component: Child }] }

B. { path: '/parent/child', component: Child }

C. { path: '/parent', component: Parent, child: [{ path: 'child', component: Child }] }

D. { path: '/parent', component: Parent, children: { path: 'child', component: Child } }

Solution

1. Step 1: Recall Vue Router child route syntax

   Child routes go inside a children array property of the parent route object.

2. Step 2: Check each option's structure

   { path: '/parent', component: Parent, children: [{ path: 'child', component: Child }] } correctly uses children: [{ path: 'child', component: Child }]. Options C and D use wrong keys or types. { path: '/parent/child', component: Child } defines a separate route, not nested.

3. Final Answer:

   { path: '/parent', component: Parent, children: [{ path: 'child', component: Child }] } -> Option A

4. Quick Check:

   Child routes = inside children array [OK]

Hint: Child routes go inside a children array in parent route [OK]

Common Mistakes:

• Using 'child' instead of 'children' key
• Defining child routes outside parent route
• Using object instead of array for children

3. Given this route config and components, what will be rendered when navigating to /dashboard/settings?

const routes = [
  { path: '/dashboard', component: Dashboard, children: [
    { path: 'settings', component: Settings }
  ]}
];

// Dashboard.vue template:
// 
Dashboard

// Settings.vue template:
// 
Settings Page

medium

A. Nothing renders due to missing

B. Settings Page

C. DashboardSettings Page

D. Dashboard

Solution

1. Step 1: Understand nested route rendering

   When visiting '/dashboard/settings', Vue renders Dashboard component first, then inside its <router-view /> renders Settings component.

2. Step 2: Combine rendered HTML from both components

   Dashboard shows <h1>Dashboard</h1> and Settings shows <h2>Settings Page</h2>. Both appear together.

3. Final Answer:

   <h1>Dashboard</h1><h2>Settings Page</h2> -> Option C

4. Quick Check:

   Nested route renders parent + child views [OK]

Hint: Nested routes render parent plus child inside [OK]

Common Mistakes:

• Expecting only child component to render
• Forgetting in parent
• Confusing full path with child path

4. What is wrong with this route configuration if child views do not appear?

const routes = [
  { path: '/profile', component: Profile, children: [
    { path: 'edit', component: EditProfile }
  ]}
];

// Profile.vue template:
// 
Profile Page

medium

A. Profile.vue is missing to display child routes

B. Child route path should start with '/'

C. Children array should be outside the parent route object

D. EditProfile component must be imported inside Profile.vue

Solution

1. Step 1: Check how child routes display

   Child routes render inside the parent's <router-view />. Without it, child views won't show.

2. Step 2: Inspect Profile.vue template

   Profile.vue only has <h1>Profile Page</h1> and no <router-view />, so child routes can't render.

3. Final Answer:

   Profile.vue is missing <router-view /> to display child routes -> Option A

4. Quick Check:

   Missing <router-view /> = no child views [OK]

Hint: Parent needs to show child routes [OK]

Common Mistakes:

• Adding '/' at start of child path incorrectly
• Placing children outside parent route object
• Assuming child component imports affect rendering

5. You want to create a nested route where /shop shows a Shop component and /shop/products shows a Products component inside Shop. Which setup correctly achieves this and ensures accessibility and responsiveness? A) Define routes with children array, use <router-view /> in Shop, and add ARIA roles and responsive CSS. B) Define separate routes for /shop and /shop/products without nesting, and use CSS media queries only. C) Use nested routes but omit <router-view /> in Shop and rely on v-if to show Products. D) Use nested routes with children but place <router-view /> outside Shop component.

hard

A. Use nested routes but place outside Shop component

B. Define separate routes without nesting and use only CSS media queries

C. Use nested routes but omit in Shop and use v-if for Products

D. Define routes with children array, use in Shop, add ARIA roles and responsive CSS

Solution

1. Step 1: Setup nested routes properly

   Use a children array in the /shop route to define /shop/products as a child route.

2. Step 2: Ensure Shop component includes <router-view />

   This allows Products component to render inside Shop when navigating to /shop/products.

3. Step 3: Add accessibility and responsiveness

   Use ARIA roles for landmarks and semantic HTML, plus responsive CSS (like Flexbox or Grid) to adapt layout on different screens.

4. Final Answer:

   Define routes with children array, use <router-view /> in Shop, add ARIA roles and responsive CSS -> Option D

5. Quick Check:

   Nested routes + router-view + accessibility + responsive CSS = Define routes with children array, use in Shop, add ARIA roles and responsive CSS [OK]

Hint: Nested routes need router-view in parent plus ARIA and responsive CSS [OK]

Common Mistakes:

• Omitting router-view in parent component
• Not adding ARIA roles for accessibility
• Ignoring responsive design in CSS
• Placing router-view outside parent component