Using stores in components in Vue - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the store in a Vue component.

Vue

<script setup>
import { [1] } from '@/stores/counter'
</script>

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

AdefineStore

BcreateStore

CuseCounterStore

DuseStore

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'createStore' which is for creating a store, not importing it.

Using 'defineStore' which is used inside the store file, not for importing.

Using a generic 'useStore' which may not exist.

You import the store function by its name, usually starting with 'use' followed by the store name, here 'useCounterStore'.

2fill in blank

medium

Complete the code to create a store instance inside the component.

Vue

<script setup>
import { useCounterStore } from '@/stores/counter'
const counter = [1]()
</script>

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

AuseCounterStore

BcreateStore

CdefineStore

DuseStore

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to call 'createStore' which is not imported here.

Using 'defineStore' which is for defining stores, not using them.

Using 'useStore' which is not imported.

You call the imported store function to get the store instance inside the component.

3fill in blank

hard

Fix the error in accessing the store's state property.

Vue

<template>
  <p>Count: {{ counter.[1] }}</p>
</template>

<script setup>
import { useCounterStore } from '@/stores/counter'
const counter = useCounterStore()
</script>

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

Acounter

Bstate

Cvalue

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to use 'state' which is not reactive in template.

Using 'value' which is for refs, not store state.

Using 'counter' which is the store instance, not a property.

You access the state property directly by its name, here 'count', not 'state' or 'value'.

4fill in blank

hard

Fill both blanks to call a store action and update the count.

Vue

<script setup>
import { useCounterStore } from '@/stores/counter'
const counter = useCounterStore()
counter.[1]([2])
</script>

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

Aincrement

B5

Cdecrement

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'decrement' instead of 'increment' when increasing count.

Passing 10 instead of 5 as argument.

Calling the action without parentheses.

You call the 'increment' action with the number 5 to increase the count by 5.

5fill in blank

hard

Fill all three blanks to create a reactive computed property from the store's count.

Vue

<script setup>
import { useCounterStore } from '@/stores/counter'
import { computed } from 'vue'
const counter = useCounterStore()
const doubleCount = computed(() => counter.[1] * [2])
const tripleCount = computed(() => counter.[3] * 3)
</script>

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

Acount

B2

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'value' which is not a store property.

Mixing up multipliers or property names.

Not using computed for reactive calculations.

You access 'count' from the store and multiply by 2 and 3 for double and triple counts.

Practice

1. What is the main purpose of using a store in a Vue component?

easy

A. To share and manage state across multiple components easily

B. To style components with CSS variables

C. To handle component lifecycle hooks

D. To define routes for navigation

Solution

1. Step 1: Understand what a store does

   A store holds shared data that multiple components can access and update.

2. Step 2: Identify the purpose in Vue components

   Stores help components share and manage state without passing props or events repeatedly.

3. Final Answer:

   To share and manage state across multiple components easily -> Option A

4. Quick Check:

   Store = Shared state management [OK]

Hint: Stores share data between components without props [OK]

Common Mistakes:

• Confusing stores with styling or routing
• Thinking stores handle lifecycle hooks
• Assuming stores are only for single components

2. Which is the correct way to import and use a Pinia store inside a Vue component's setup() function?

easy

A. import store from 'pinia'

B. const store = createStore()

C. const store = useStore()

D. const store = new Store()

Solution

1. Step 1: Recall Pinia store usage

   Pinia stores are accessed inside components by calling the store function, usually named useStore().

2. Step 2: Check the options

   Only const store = useStore() correctly calls the store function inside setup().

3. Final Answer:

   const store = useStore() -> Option C

4. Quick Check:

   Use useStore() to access store [OK]

Hint: Call useStore() inside setup() to get the store [OK]

Common Mistakes:

• Trying to import store directly from 'pinia'
• Using createStore() which is Vuex syntax
• Using new Store() which is not valid in Pinia

3. Given this Pinia store code:

import { defineStore } from 'pinia'
export const useCounterStore = defineStore('counter', {
  state: () => ({ count: 0 }),
  actions: {
    increment() { this.count++ }
  }
})

And this component code:

const counter = useCounterStore()
counter.increment()
console.log(counter.count)

What will be logged to the console?

medium

A. NaN

B. 0

C. undefined

D. 1

Solution

1. Step 1: Understand the store state and action

   The store starts with count = 0. Calling increment() increases count by 1.

2. Step 2: Trace the component code

   After calling counter.increment(), counter.count becomes 1, so logging it prints 1.

3. Final Answer:

   1 -> Option D

4. Quick Check:

   Increment changes count from 0 to 1 [OK]

Hint: increment() adds 1 to count, so output is 1 [OK]

Common Mistakes:

• Expecting count to stay 0 without calling increment
• Confusing state with undefined
• Thinking increment returns a value

4. What is wrong with this Vue component code using a Pinia store?

import { useCounterStore } from '@/stores/counter'
export default {
  setup() {
    const counter = useCounterStore
    counter.increment()
    return { counter }
  }
}

medium

A. useCounterStore is not called as a function

B. increment() is not a valid action

C. counter should be imported from 'pinia' instead

D. setup() should return a function

Solution

1. Step 1: Check how the store is used

   The code assigns counter = useCounterStore without parentheses, so it stores the function itself, not the store instance.

2. Step 2: Understand the effect

   Calling counter.increment() fails because counter is a function, not the store object.

3. Final Answer:

   useCounterStore is not called as a function -> Option A

4. Quick Check:

   Call useCounterStore() to get store instance [OK]

Hint: Always call useCounterStore() with () [OK]

Common Mistakes:

• Forgetting parentheses when calling store function
• Assuming increment() is invalid
• Confusing import source for store

5. You want to create a Vue component that uses a Pinia store to track a list of tasks. You need to add a new task only if it is not empty and not already in the list. Which code snippet correctly uses the store inside setup() to achieve this?

hard

A. const taskStore = useTaskStore
function addTask(task) {
if (taskStore.tasks.indexOf(task) === -1) {
taskStore.tasks.push(task)
}
}

B. const taskStore = useTaskStore()
function addTask(task) {
if (task && !taskStore.tasks.includes(task)) {
taskStore.tasks.push(task)
}
}

C. const taskStore = useTaskStore()
function addTask(task) {
if (task !== '') {
taskStore.tasks = [...taskStore.tasks, task]
}
}

D. const taskStore = useTaskStore()
function addTask(task) {
taskStore.tasks.push(task)
}

Solution

1. Step 1: Check store usage and function call

   const taskStore = useTaskStore()
   function addTask(task) {
     if (task && !taskStore.tasks.includes(task)) {
       taskStore.tasks.push(task)
     }
   

   correctly calls useTaskStore() to get the store instance and defines addTask with proper checks.

2. Step 2: Verify conditions for adding task

   It checks if task is not empty and not already in taskStore.tasks before pushing, preventing duplicates and empty entries.

3. Final Answer:

   correctly uses the store and conditions to add tasks safely -> Option B

4. Quick Check:

   Call store with () and check conditions before push [OK]

Hint: Call store with () and check duplicates before push [OK]

Common Mistakes:

• Not calling useTaskStore() as a function
• Not checking for empty or duplicate tasks
• Replacing tasks array instead of pushing