Accessing keys and arguments in Redis - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the first key in a Redis Lua script.

Redis

local key1 = KEYS[[1]]

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

A1

B0

C2

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as the index which causes an error.

Trying to access keys by name instead of index.

In Redis Lua scripts, keys are accessed starting at index 1, so KEYS[1] gets the first key.

2fill in blank

medium

Complete the code to access the second argument passed to the Redis Lua script.

Redis

local arg2 = ARGV[[1]]

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

A2

Barg

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as index which is invalid in Lua.

Confusing KEYS and ARGV tables.

ARGV holds the arguments passed to the script starting at index 1, so ARGV[2] is the second argument.

3fill in blank

hard

Fix the error in accessing the first key in the script.

Redis

local firstKey = KEYS[[1]]

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

Afirst

B0

Ckey1

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as index causing nil value.

Using string keys instead of numeric indices.

Lua tables start at 1, so KEYS[1] correctly accesses the first key.

4fill in blank

hard

Fill both blanks to get the third key and the first argument in the script.

Redis

local thirdKey = KEYS[[1]]
local firstArg = ARGV[[2]]

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

A3

B1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as index which is invalid.

Mixing up keys and arguments indices.

KEYS[3] accesses the third key, and ARGV[1] accesses the first argument.

5fill in blank

hard

Fill all three blanks to get the second key, the third argument, and the first key in the script.

Redis

local secondKey = KEYS[[1]]
local thirdArg = ARGV[[2]]
local firstKey = KEYS[[3]]

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

A1

B3

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as index causing errors.

Confusing keys and arguments indices.

KEYS[2] is the second key, ARGV[3] is the third argument, and KEYS[1] is the first key.