Why lists handle ordered sequences in Redis - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add an element to the end of a Redis list.

Redis

LPUSH mylist [1]

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

Aelement

Bmylist

CLPOP

DRPOP

Attempts:

3 left

💡 Hint

Common Mistakes

Using the list name instead of the element as the second argument.

Confusing LPUSH with LPOP or RPOP commands.

The LPUSH command adds an element to the start of the list. Here, you need to specify the element to add.

2fill in blank

medium

Complete the code to retrieve all elements from a Redis list.

Redis

LRANGE mylist [1] -1

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

A10

B-1

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using -1 as the start index, which returns an empty list.

Using 1 as the start index, which skips the first element.

The LRANGE command gets elements from a list between two indexes. Starting at 0 gets all elements from the start.

3fill in blank

hard

Fix the error in the code to remove the last element from a Redis list.

Redis

[1] mylist

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

ALPOP

BRPOP

CLPUSH

DRPUSH

Attempts:

3 left

💡 Hint

Common Mistakes

Using LPUSH or RPUSH which add elements instead of removing.

Using LPOP which removes the first element, not the last.

The RPOP command removes and returns the last element of the list.

4fill in blank

hard

Fill both blanks to add an element to the end and then get the last element from a Redis list.

Redis

RPUSH mylist [1]
[2] mylist

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

Aelement

BRPOP

CLPOP

Dmylist

Attempts:

3 left

💡 Hint

Common Mistakes

Using LPOP instead of RPOP to remove the last element.

Using the list name as the element to add.

RPUSH adds an element to the end of the list. RPOP removes and returns the last element.

5fill in blank

hard

Fill all three blanks to add an element to the start, get the first element, and remove it from a Redis list.

Redis

LPUSH mylist [1]
[2] mylist 0 0
[3] mylist

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

Aelement

BLRANGE

CLPOP

DRPUSH

Attempts:

3 left

💡 Hint

Common Mistakes

Using RPUSH instead of LPUSH to add to the start.

Using RPOP instead of LPOP to remove the first element.

Using LRANGE with wrong indexes.

LPUSH adds an element to the start. LRANGE mylist 0 0 gets the first element. LPOP removes the first element.