Storing and retrieving cache in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is caching in Laravel?

Caching in Laravel means saving data temporarily to speed up your app by avoiding repeated work.

beginner

How do you store data in cache using Laravel's Cache facade?

Use Cache::put('key', 'value', seconds) to save data with a key and expiration time.

beginner

How to retrieve cached data in Laravel?

Use Cache::get('key') to get the stored value by its key. If key not found, returns null or default.

intermediate

What happens if you try to get a cache key that does not exist?

Laravel returns null or a default value if provided, so your app can handle missing cache safely.

intermediate

How can you check if a cache key exists in Laravel?

Use Cache::has('key') which returns true if the key exists and false if not.

Which method stores data in Laravel cache?

A Cache::has()

B Cache::put()

C Cache::get()

D Cache::forget()

Cache::put() saves data in the cache with a key and expiration time.

What does Cache::get('key') return if the key is missing?

A Throws an error

B Creates the key automatically

C Returns false

D Returns null or default value

Cache::get() returns null or a default value if the key does not exist.

How do you check if a cache key exists in Laravel?

A Cache::has('key')

B Cache::exists('key')

C Cache::check('key')

D Cache::find('key')

Cache::has('key') returns true if the key exists in cache.

Which of these is NOT a valid cache operation in Laravel?

A Cache::delete()

B Cache::get()

C Cache::put()

D Cache::forget()

Cache::delete() is not a Laravel method; use Cache::forget() to remove keys.

What parameter is required when storing cache with Cache::put()?

A Only key

B Only key and value

C Key, value, and expiration time

D Only value and expiration time

Cache::put() requires a key, value, and expiration time (or a DateTime instance). Expiration time is optional but recommended.

Explain how to store and retrieve data from cache in Laravel with examples.

Think about saving and reading data quickly to avoid repeating work.

Describe how Laravel helps check if cached data exists and how to handle missing cache keys.

Consider how your app stays safe when cache is empty.

Practice

1. What does the Cache::put('key', 'value', 60) method do in Laravel?

easy

A. Stores 'value' permanently in cache without expiration

B. Retrieves 'value' from cache with 'key' and expires in 60 seconds

C. Deletes the cache entry with 'key' after 60 minutes

D. Stores 'value' in cache under 'key' for 60 minutes

Solution

1. Step 1: Understand Cache::put method

   The Cache::put method stores data in the cache with a key and expiration time in minutes.

2. Step 2: Analyze the parameters

   Here, 'key' is the cache key, 'value' is the data stored, and 60 means it expires after 60 minutes.

3. Final Answer:

   Stores 'value' in cache under 'key' for 60 minutes -> Option D

4. Quick Check:

   Cache::put stores with expiration = A [OK]

Hint: Cache::put stores with minutes expiry, not seconds [OK]

Common Mistakes:

• Confusing expiration time units (seconds vs minutes)
• Thinking Cache::put retrieves data
• Assuming Cache::put stores data permanently

2. Which of the following is the correct syntax to retrieve a cached value with a default fallback in Laravel?

easy

A. Cache::get('key', 'default')

B. Cache::retrieve('key', 'default')

C. Cache::fetch('key', 'default')

D. Cache::find('key', 'default')

Solution

1. Step 1: Identify Laravel cache retrieval method

   Laravel uses Cache::get to retrieve cached data safely.

2. Step 2: Check method parameters

   The second parameter is the default value returned if the key is not found.

3. Final Answer:

   Cache::get('key', 'default') -> Option A

4. Quick Check:

   Cache::get with default = A [OK]

Hint: Use Cache::get to retrieve with default fallback [OK]

Common Mistakes:

• Using non-existent methods like retrieve or fetch
• Forgetting the default fallback parameter
• Using Cache::put instead of Cache::get

3. What will be the output of this Laravel code snippet?

Cache::put('count', 5, 10);
$value = Cache::get('count', 0);
echo $value;

medium

A. 0

B. null

C. 5

D. Error

Solution

1. Step 1: Store value in cache

   The code stores the integer 5 under the key 'count' with expiration 10 minutes.

2. Step 2: Retrieve value from cache

   Then it retrieves 'count' with default 0. Since the key exists, it returns 5.

3. Final Answer:

   5 -> Option C

4. Quick Check:

   Cache::get returns stored value if exists = B [OK]

Hint: Cache::get returns stored value, not default if key exists [OK]

Common Mistakes:

• Assuming default value is always returned
• Confusing expiration time with immediate deletion
• Expecting null or error instead of stored value

4. Identify the error in this Laravel cache usage:

Cache::put('user', 'Alice');
$value = Cache::get('user');
echo $value;

medium

A. Cache::put requires expiration time as third argument

B. Cache::get requires a default value parameter

C. Cache::put key must be numeric

D. Cache::get cannot be used without Cache::forever

Solution

1. Step 1: Check Cache::put usage

   Cache::put requires three parameters: key, value, and expiration time in minutes.

2. Step 2: Identify missing expiration

   The code misses the expiration time, so it will cause an error or unexpected behavior.

3. Final Answer:

   Cache::put requires expiration time as third argument -> Option A

4. Quick Check:

   Cache::put needs expiration time = D [OK]

Hint: Always provide expiration time with Cache::put unless using forever [OK]

Common Mistakes:

• Omitting expiration time in Cache::put
• Thinking Cache::get always needs default
• Believing keys must be numeric

5. You want to store a user's settings permanently in cache and then remove them later. Which sequence of Laravel cache methods is correct?

hard

A. Cache::store('settings', $data); Cache::remove('settings');

B. Cache::forever('settings', $data); Cache::forget('settings');

C. Cache::put('settings', $data, 0); Cache::delete('settings');

D. Cache::save('settings', $data); Cache::clear('settings');

Solution

1. Step 1: Store data permanently

   Use Cache::forever to store data without expiration.

2. Step 2: Remove cached data

   Use Cache::forget to delete the cached key when needed.

3. Final Answer:

   Cache::forever('settings', $data); Cache::forget('settings'); -> Option B

4. Quick Check:

   Permanent store + forget = C [OK]

Hint: Use forever to store permanently, forget to delete [OK]

Common Mistakes:

• Using wrong method names like delete or remove
• Passing 0 as expiration to put for permanent storage
• Confusing Cache::store or Cache::save as valid methods