Cache tags in Laravel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to store a cache item with a tag.

Laravel

Cache::tags('[1]')->put('key', 'value', 60);

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

Ausers

Bsession

Ccache

Dconfig

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method other than tags() to assign tags.

Passing an array instead of a string for a single tag.

The tags method accepts the tag name as a string to group cache items.

2fill in blank

medium

Complete the code to retrieve a cached item with a tag.

Laravel

$value = Cache::tags('users')->[1]('key');

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

Aget

Bstore

Cput

Dforget

Attempts:

3 left

💡 Hint

Common Mistakes

Using put instead of get to retrieve data.

Using forget which deletes the cache.

The get method retrieves the cached value by key.

3fill in blank

hard

Fix the error in the code to clear all cache items with the 'users' tag.

Laravel

Cache::tags('users')->[1]();

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

Aforget

Bflush

Cclear

Dremove

Attempts:

3 left

💡 Hint

Common Mistakes

Using clear which is not a valid method.

Using forget which only deletes one key.

The flush method clears all cache items for the given tags.

4fill in blank

hard

Fill both blanks to store a cache item with multiple tags.

Laravel

Cache::tags([[1], [2]])->put('key', 'value', 120);

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

A'users'

B'settings'

C'config'

D'session'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing tags as a comma-separated string instead of an array.

Using invalid tag names.

Multiple tags are passed as an array of strings to the tags method.

5fill in blank

hard

Fill all three blanks to retrieve a cached item with multiple tags and a default value.

Laravel

$value = Cache::tags([[1], [2]])->get('key', [3]);

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

A'users'

B'settings'

C'default'

D'cache'

Attempts:

3 left

💡 Hint

Common Mistakes

Not passing tags as an array.

Omitting the default value parameter.

The get method accepts a default value returned if the key is missing. Multiple tags are passed as an array.

Practice

1. What is the main purpose of using cache tags in Laravel?

easy

A. To group cached items for easy management and selective clearing

B. To encrypt cached data automatically

C. To increase cache storage size

D. To log cache hits and misses

Solution

1. Step 1: Understand cache tags concept

   Cache tags allow grouping of cached items under one or more tags.

2. Step 2: Identify the benefit of grouping

   This grouping helps to clear or manage all related cache items easily by tag.

3. Final Answer:

   To group cached items for easy management and selective clearing -> Option A

4. Quick Check:

   Cache tags = group and manage cache [OK]

Hint: Cache tags group items for easy clearing [OK]

Common Mistakes:

• Thinking tags encrypt data
• Assuming tags increase cache size
• Confusing tags with logging features

2. Which of the following is the correct syntax to store a cache item with a tag in Laravel?

easy

A. Cache::tags('users')->put('user_1', 'John', 3600);

B. Cache::put('user_1', 'John')->tags(['users'], 3600);

C. Cache::put('user_1', 'John', 3600)->tags(['users']);

D. Cache::tags(['users'])->put('user_1', 'John', 3600);

Solution

1. Step 1: Recall Laravel cache tag syntax

   The tags() method accepts an array of tags before calling put().

2. Step 2: Check method chaining order

   The correct order is Cache::tags([...])->put(key, value, time).

3. Final Answer:

   Cache::tags(['users'])->put('user_1', 'John', 3600); -> Option D

4. Quick Check:

   tags() before put() with array [OK]

Hint: Use tags() with array before put() [OK]

Common Mistakes:

• Passing tags after put()
• Using string instead of array in tags()
• Chaining methods in wrong order

3. Given the code below, what will be the output of Cache::tags(['products'])->get('item_1'); after Cache::tags(['products'])->flush(); is called?

Cache::tags(['products'])->put('item_1', 'Book', 600);
Cache::tags(['products'])->flush();
$value = Cache::tags(['products'])->get('item_1');
echo $value ?? 'Not found';

medium

A. Not found

B. CacheException

C. null

D. Book

Solution

1. Step 1: Understand flush() effect on tagged cache

   Calling flush() on a tag clears all cached items under that tag.

2. Step 2: Check retrieval after flush

   After flushing, get('item_1') returns null, so the null coalescing operator outputs 'Not found'.

3. Final Answer:

   Not found -> Option A

4. Quick Check:

   flush() clears tagged cache = 'Not found' [OK]

Hint: flush() clears all tagged cache items [OK]

Common Mistakes:

• Expecting cached value after flush
• Confusing flush() with forget()
• Assuming flush() only clears one item

4. Identify the error in the following Laravel cache tag usage:

Cache::tags('sessions')->put('session_1', 'data', 120);
Cache::tags(['sessions'])->flush();

medium

A. Missing cache driver configuration

B. Using string instead of array in tags() method

C. Calling flush() on tags is not allowed

D. put() method requires a closure

Solution

1. Step 1: Check tags() method argument type

   The tags() method requires an array of tags, not a string.

2. Step 2: Identify the incorrect usage

   Passing a string 'sessions' instead of ['sessions'] causes an error.

3. Final Answer:

   Using string instead of array in tags() method -> Option B

4. Quick Check:

   tags() needs array, not string [OK]

Hint: Always pass array to tags() [OK]

Common Mistakes:

• Passing single string instead of array
• Thinking flush() is disallowed
• Assuming put() needs closure

5. You want to cache user profile data and product data separately but clear both caches together when needed. Which is the best way to use cache tags in Laravel to achieve this?

hard

A. Tag user profiles with ['users'] and products with ['products'], then flush both tags separately

B. Use no tags and clear cache manually by keys

C. Tag both user profiles and products with ['app_data'], then flush this tag to clear all

D. Tag user profiles with ['users'] and products with ['products'], then flush(['users', 'products'])

Solution

1. Step 1: Understand grouping with tags

   To clear multiple cache groups together, use a common tag for both.

2. Step 2: Apply a shared tag

   Tag both user and product caches with a shared tag like 'app_data' to flush all at once.

3. Final Answer:

   Tag both user profiles and products with ['app_data'], then flush this tag to clear all -> Option C

4. Quick Check:

   Shared tag groups caches for joint flush [OK]

Hint: Use shared tag to clear multiple caches together [OK]

Common Mistakes:

• Flushing tags separately instead of shared tag
• Not tagging caches for group clearing
• Trying to flush multiple tags in one call incorrectly