List vs sorted set for sequences in Redis - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

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

Redis

redis-cli RPUSH mylist [1]

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

Aelement

Bmylist

CZADD

DSADD

Attempts:

3 left

💡 Hint

Common Mistakes

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

Confusing RPUSH with ZADD or SADD commands.

RPUSH adds the specified element to the end of the list named 'mylist'.

2fill in blank

medium

Complete the code to add an element with a score to a Redis sorted set.

Redis

redis-cli ZADD myzset [1] element

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

Ascore

BZREM

Cmyzset

Delement

Attempts:

3 left

💡 Hint

Common Mistakes

Using the element name instead of the score.

Confusing ZADD with ZREM or other commands.

ZADD requires the sorted set name, a score, and the element to add. The score determines the order.

3fill in blank

hard

Fix the error in the command to get the first 3 elements from a Redis list.

Redis

redis-cli LRANGE mylist [1] 2

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A-1

B0

C1

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Starting at 1 instead of 0, which skips the first element.

Using 3 as start index which is out of range.

LRANGE uses zero-based indexes. To get the first 3 elements, start at 0 and end at 2.

4fill in blank

hard

Fill both blanks to retrieve elements with scores between 10 and 20 from a sorted set.

Redis

redis-cli ZRANGEBYSCORE myzset [1] [2]

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

A10

B20

C-inf

D+inf

Attempts:

3 left

💡 Hint

Common Mistakes

Using -inf or +inf instead of specific score values.

Swapping min and max values.

ZRANGEBYSCORE returns elements with scores between the given min and max values, inclusive.

5fill in blank

hard

Fill all three blanks to add an element with score 15 and then retrieve elements with scores between 10 and 20.

Redis

redis-cli [1] myzset [2] element && redis-cli ZRANGEBYSCORE myzset 10 20

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

AZADD

B15

Cmyzset

DSADD

Attempts:

3 left

💡 Hint

Common Mistakes

Using SADD instead of ZADD for sorted sets.

Mixing up the order of arguments.

First, use ZADD to add 'element' with score 15 to 'myzset'. Then use ZRANGEBYSCORE to get elements with scores between 10 and 20.