SET and GET commands in Redis - Step-by-Step Execution

Concept Flow - SET and GET commands

Start

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SET key value

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Store value in key

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GET key

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Retrieve value

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Output value

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End

The flow shows storing a value with SET, then retrieving it with GET, and finally outputting the stored value.

Execution Sample

Redis

SET name "Alice"
GET name

Stores the value "Alice" under the key "name" and then retrieves it.

Execution Table

Step	Command	Action	Key	Value Stored	Output
1	SET name "Alice"	Store value	name	"Alice"	OK
2	GET name	Retrieve value	name	"Alice"	"Alice"
3	GET age	Retrieve value	age	null	(nil)

💡 No more commands to execute.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3
name	null	"Alice"	"Alice"	"Alice"
age	null	null	null	null

Key Moments - 2 Insights

Why does GET return (nil) when the key does not exist?

GET returns (nil) because the key is not found in the database, as shown in step 3 of the execution_table where 'age' was never set.

What does SET command output after storing a value?

SET outputs 'OK' to confirm the value was stored successfully, as seen in step 1 of the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what is the output of the SET command at step 1?

A OK

B "Alice"

C (nil)

D Error

💡 Hint

Check the Output column in row for step 1 in execution_table.

At which step does GET return (nil) because the key does not exist?

A Step 1

B Step 2

C Step 3

D None

💡 Hint

Look at the Output column in execution_table for step 3.

If we SET key 'age' to '30' after step 3, what will GET age return?

A (nil)

B "30"

C OK

D Error

💡 Hint

Refer to how SET stores values and GET retrieves them as shown in steps 1 and 2.

Concept Snapshot

SET key value - stores a value under a key
GET key - retrieves the value stored
If key does not exist, GET returns (nil)
SET returns OK on success
GET returns the stored value as a string

Full Transcript

This visual execution shows how Redis commands SET and GET work. First, SET stores a value under a key and returns OK. Then GET retrieves the value for that key. If the key does not exist, GET returns (nil). The variable tracker shows how keys and values change after each command. This helps beginners see exactly what happens step-by-step.