EXPIRE and TTL for time-to-live in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a key to expire after 60 seconds.

Redis

EXPIRE mykey [1]

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

A6

B600

C60

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 will delete the key immediately.

Using 600 sets expiration to 10 minutes, not 1 minute.

The EXPIRE command sets the time-to-live in seconds. Here, 60 means the key expires after 60 seconds.

2fill in blank

medium

Complete the code to check the remaining time to live of a key.

Redis

TTL [1]

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

Amykey

Bsession

Cexpire

Dtimeout

Attempts:

3 left

💡 Hint

Common Mistakes

Using a command name instead of a key name.

Using a key that does not exist returns -2.

The TTL command returns the remaining time to live of the key 'mykey'.

3fill in blank

hard

Fix the error in the command to set expiration to 120 seconds.

Redis

EXPIRE mykey [1]

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

A1m

B120

Ctwo_minutes

D-120

Attempts:

3 left

💡 Hint

Common Mistakes

Using text instead of a number.

Using negative numbers.

The EXPIRE command requires the time in seconds as a number. '120' is correct. Strings like 'two_minutes' or '1m' are invalid. Negative numbers are invalid.

4fill in blank

hard

Fill both blanks to set a key to expire and then check its TTL.

Redis

EXPIRE [1] 30
TTL [2]

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

Acache

Bsession

Attempts:

3 left

💡 Hint

Common Mistakes

Using different key names in EXPIRE and TTL commands.

Using a key that does not exist.

We set expiration on the key 'cache' and then check TTL on the same key 'cache'.

5fill in blank

hard

Fill all three blanks to set a key expiration, check TTL, and remove expiration.

Redis

EXPIRE [1] 45
TTL [2]
PERSIST [3]

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

Atempkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using different key names in commands.

Confusing PERSIST with EXPIRE.

We set expiration on 'tempkey', check its TTL, then remove expiration with PERSIST on the same key 'tempkey'.