SETNX for set-if-not-exists in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a key only if it does not exist.

Redis

SETNX mykey [1]

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

Avalue

BEX

CNX

DPX

Attempts:

3 left

💡 Hint

Common Mistakes

Using expiration options like EX or PX instead of the value.

Confusing SETNX with SET command options.

The SETNX command sets the key to the given value only if the key does not already exist.

2fill in blank

medium

Complete the command to set key 'user' with value 'Alice' only if it does not exist.

Redis

SETNX [1] Alice

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

Aname

Buser

Cusername

Duser_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different key name than 'user'.

Confusing the key with the value.

The key to set is user, so the command sets 'user' to 'Alice' if 'user' does not exist.

3fill in blank

hard

Fix the error in the command to set key 'session' with value 'abc123' only if it does not exist.

Redis

SETNX session [1]

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

ASET

B'abc123'

Csession

Dabc123

Attempts:

3 left

💡 Hint

Common Mistakes

Adding quotes around the value.

Using the key name as the value.

The value should be abc123 without quotes in Redis CLI commands.

4fill in blank

hard

Fill both blanks to set key 'config' with value 'enabled' only if it does not exist, and check the result.

Redis

SETNX [1] [2]

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

Aconfig

Benabled

Csettings

Ddisabled

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping key and value.

Using wrong key or value names.

The key is config and the value is enabled. The command sets the key only if it does not exist.

5fill in blank

hard

Fill all three blanks to set key 'flag' with value 'true' only if it does not exist, then get the key.

Redis

SETNX [1] [2]
GET [3]

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

Aflag

Btrue

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using different keys in SETNX and GET.

Using wrong values like 'false'.

The key is flag, the value is true, and the GET command retrieves the value of flag.