PSUBSCRIBE for pattern matching in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to subscribe to all channels starting with 'news.'.

Redis

PSUBSCRIBE [1]

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

Anews+

Bnews?

Cnews.*

Dnews#

Attempts:

3 left

💡 Hint

Common Mistakes

Using '?' which matches exactly one character, not any sequence.

Using '+' or '#' which are not valid Redis pattern wildcards.

The pattern 'news.*' matches all channels starting with 'news.' followed by any characters.

2fill in blank

medium

Complete the code to subscribe to all channels ending with '.update'.

Redis

PSUBSCRIBE [1]

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

A+.update

B?update

C#.update

D*.update

Attempts:

3 left

💡 Hint

Common Mistakes

Using '?' which matches only one character.

Using '+' or '#' which are not Redis wildcards.

The pattern '*.update' matches any channel name that ends with '.update'.

3fill in blank

hard

Fix the error in the pattern to subscribe to channels with exactly one character after 'log'.

Redis

PSUBSCRIBE [1]

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

Alog?

Blog.*

Clog+

Dlog#

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' which matches any number of characters, not exactly one.

Using '+' or '#' which are invalid in Redis patterns.

The '?' wildcard matches exactly one character, so 'log?' matches channels like 'log1' or 'loga'.

4fill in blank

hard

Fill both blanks to subscribe to the channels 'chat.room1' and 'chat.room2'.

Redis

PSUBSCRIBE [1] [2]

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

Achat.room1

Bchat.room2

Cchat.*

D*.room1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'chat.*' which matches all channels starting with 'chat.', not just room1 or room2.

Using '*.room1' which matches any channel ending with 'room1', not starting with 'chat.'.

To subscribe to specific channels 'chat.room1' and 'chat.room2', list both patterns explicitly.

5fill in blank

hard

Fill all three blanks to subscribe to channels matching these patterns: any channel starting with 'user.', any channel ending with '.alert', and any channel containing 'error'.

Redis

PSUBSCRIBE [1] [2] [3]

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

Auser.*

B*.alert

C*error*

Derror.*

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'error.*' which matches channels starting with 'error.', not containing 'error' anywhere.

Using patterns without '*' which won't match variable parts.

The patterns 'user.*', '*.alert', and '*error*' match the required channel names for subscription.