Route parameters with useRoute in Vue

Introduction

Route parameters let you get values from the URL.
useRoute helps you read these values inside your Vue component easily.

You want to show details of a user based on their ID in the URL.

You need to get a product code from the URL to display product info.

You want to read a category name from the URL to filter a list.

You want to react to changes in the URL parameters without reloading the page.

Syntax

Vue

import { useRoute } from 'vue-router'

const route = useRoute()
const paramValue = route.params.paramName

useRoute is a function from vue-router to access current route info.

Route parameters are accessed via route.params object.

Examples

Get the id parameter from the URL, like /user/123.

Vue

const route = useRoute()
const userId = route.params.id

Read a category parameter from the URL, e.g. /shop/electronics.

Vue

const route = useRoute()
const category = route.params.category

Get a slug parameter or use a default if missing.

Vue

const route = useRoute()
const slug = route.params.slug || 'default-slug'

Sample Program

This component shows the user ID from the URL parameter id. If the URL is /user/42, it displays 42. It updates automatically if the URL changes.

Vue

<template>
  <main>
    <h1>User Profile</h1>
    <p>User ID from URL: {{ userId }}</p>
  </main>
</template>

<script setup>
import { useRoute } from 'vue-router'
import { computed } from 'vue'

const route = useRoute()
const userId = computed(() => route.params.id || 'No ID')
</script>

Important Notes

Route parameters come from the route path like /user/:id.

useRoute returns a reactive object, so use computed to react to changes.

If the parameter is missing, handle it gracefully to avoid errors.

Summary

useRoute lets you read URL parameters inside Vue components.

Access parameters with route.params.paramName.

Use computed to react to parameter changes.

Practice

1. What does the useRoute function in Vue Router allow you to do inside a component?

easy

A. Access the current route's parameters and information

B. Change the URL path programmatically

C. Register a new route dynamically

D. Navigate to a different route without reloading

Solution

1. Step 1: Understand the purpose of useRoute

   useRoute is a Vue Router composable that provides access to the current route object inside a component.

2. Step 2: Identify what can be accessed with useRoute

   It allows reading route parameters, query, name, and path but does not change routes or register them.

3. Final Answer:

   Access the current route's parameters and information -> Option A

4. Quick Check:

   useRoute reads route info = B [OK]

Hint: useRoute reads route info, doesn't change or register routes [OK]

Common Mistakes:

• Thinking useRoute changes routes
• Confusing useRoute with useRouter
• Assuming useRoute registers routes

2. Which of the following is the correct way to import and use useRoute in a Vue 3 component's setup() function?

easy

A. import { useRoute } from 'vue-router'; const route = useRoute(route);

B. import useRoute from 'vue-router'; const route = useRoute();

C. import { useRoute } from 'vue-router'; const route = useRoute();

D. import { useRoute } from 'vue'; const route = useRoute();

Solution

1. Step 1: Check the import source

   useRoute is exported from 'vue-router', so import must be from 'vue-router'.

2. Step 2: Verify usage syntax

   The correct usage is calling useRoute() without arguments to get the current route object.

3. Final Answer:

   import { useRoute } from 'vue-router'; const route = useRoute(); -> Option C

4. Quick Check:

   Correct import and call = D [OK]

Hint: Import from 'vue-router' and call useRoute() with no arguments [OK]

Common Mistakes:

• Importing from 'vue' instead of 'vue-router'
• Calling useRoute with arguments
• Using default import instead of named import

3. Given this Vue 3 component code snippet, what will be logged when the URL is /user/42 and the route is defined as /user/:id?

import { useRoute } from 'vue-router';
import { onMounted } from 'vue';

export default {
  setup() {
    const route = useRoute();
    onMounted(() => {
      console.log(route.params.id);
    });
  }
}

medium

A. null

B. undefined

C. user

D. 42

Solution

1. Step 1: Identify the route parameter

   The route is defined as /user/:id, so id is a parameter expected in route.params.

2. Step 2: Check the URL and logged value

   The URL is /user/42, so route.params.id will be "42". The console logs this value on mount.

3. Final Answer:

   42 -> Option D

4. Quick Check:

   route.params.id = "42" [OK]

Hint: Route param matches URL segment after colon :id [OK]

Common Mistakes:

• Expecting param name instead of value
• Confusing params with query
• Logging before route is ready

4. What is the main issue with this Vue 3 component code that tries to react to route parameter changes?

import { useRoute } from 'vue-router';
import { computed } from 'vue';

export default {
  setup() {
    const route = useRoute();
    const userId = computed(() => route.params.id);
    return { userId };
  }
}

The component does not update userId when the route changes.

medium

A. The route object is not reactive, so computed won't update

B. The computed function is missing a dependency array

C. The useRoute hook must be called inside onMounted

D. The userId should be a ref, not computed

Solution

1. Step 1: Understand reactivity of route

   The route object returned by useRoute() is reactive, but its params property is not deeply reactive by default.

2. Step 2: Why computed does not update

   Because route.params is not reactive, the computed property does not track changes, so userId stays the same.

3. Final Answer:

   The route object is not reactive, so computed won't update -> Option A

4. Quick Check:

   Route params not reactive = A [OK]

Hint: Route params are not deeply reactive; watch route.fullPath instead [OK]

Common Mistakes:

• Assuming route.params is reactive
• Calling useRoute inside lifecycle hooks
• Using ref instead of computed incorrectly

5. You want to create a Vue 3 component that displays the user ID from the route parameter and updates automatically when the route changes. Which approach correctly achieves this?

import { useRoute } from 'vue-router';
import { computed, watch, ref } from 'vue';

export default {
  setup() {
    const route = useRoute();
    // What should userId be?
    const userId = ???
    return { userId };
  }
}

hard

A. computed(() => route.params.id)

B. computed(() => route.params.id) with a watch on route.fullPath to trigger updates

C. computed(() => route.fullPath.split('/')[2])

D. ref(route.params.id) without any watcher

Solution

1. Step 1: Understand reactivity limitations

   Route params are not deeply reactive, so computed(() => route.params.id) alone won't update when params change.

2. Step 2: Use a watch on route.fullPath to trigger updates

   Watching route.fullPath (which is reactive) and recomputing userId ensures updates when the route changes.

3. Final Answer:

   computed(() => route.params.id) with a watch on route.fullPath to trigger updates -> Option B

4. Quick Check:

   Watch route.fullPath for param changes = C [OK]

Hint: Watch route.fullPath to react to param changes in computed [OK]

Common Mistakes:

• Using computed alone without watch
• Parsing fullPath manually without reactivity
• Using ref without updating on route change