Storing and retrieving cache in Laravel - Step-by-Step Execution

Concept Flow - Storing and retrieving cache

Start

↓

Check if cache key exists

|Yes↓

Retrieve cached value

↓

Use cached value

↓

End

No↓

Generate data

↓

Store data in cache with key

↓

Use stored data

↓

End

The flow checks if a cache key exists. If yes, it retrieves and uses the cached value. If no, it generates data, stores it in cache, then uses it.

Execution Sample

Laravel

<?php
use Illuminate\Support\Facades\Cache;

$value = Cache::remember('key', 60, fn() => 'data');
return $value;

This code tries to get 'key' from cache. If missing, it stores 'data' for 60 minutes and returns it.

Execution Table

Step	Action	Cache Key Exists?	Cache Operation	Result
1	Check cache for 'key'	No	Cache miss	No value found
2	Generate data	N/A	N/A	'data' generated
3	Store 'data' in cache with key 'key' for 60 minutes	N/A	Cache store	'data' stored
4	Return stored data	N/A	N/A	'data' returned
5	End	N/A	N/A	Process complete

💡 Cache key 'key' was missing initially, so data was generated and stored, then returned.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
value	undefined	undefined	'data'	'data'	'data'

Key Moments - 2 Insights

Why does the code generate data only when the cache key is missing?

Because the execution_table row 1 shows a cache miss, so the code runs the data generation in step 2 before storing it in step 3.

What happens if the cache key exists when Cache::remember runs?

The cache returns the stored value immediately (cache hit), skipping data generation and storage, as shown in execution_table step 4.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of 'value' after step 2?

A undefined

B 'data'

C null

D 'key'

💡 Hint

Check variable_tracker column 'After Step 2' for 'value'.

At which step does the cache store the data?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at execution_table 'Cache Operation' column for 'Cache store'.

If the cache key existed initially, which step would be skipped?

A Step 2

B Step 3

C Step 1

D Step 5

💡 Hint

Refer to execution_table steps where data generation happens only on cache miss.

Concept Snapshot

Laravel cache stores data by key for a set time.
Use Cache::remember('key', minutes, callback) to get or store.
If key exists, cached value returns immediately.
If missing, callback runs, stores result, then returns it.
This avoids repeated expensive data generation.

Full Transcript

This visual trace shows how Laravel caching works using Cache::remember. First, the code checks if the cache key exists. If it does, the cached value is returned immediately. If not, the code generates the data, stores it in cache with the key for a set time, then returns the data. The variable 'value' holds the cached or generated data. This process helps avoid repeating expensive operations by reusing stored results.