TYPE command for key type check in Redis - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the Redis TYPE command do?

The TYPE command tells you the data type stored at a given key in Redis, like string, list, set, hash, stream, or none if the key doesn't exist.

beginner

How do you check the type of a key named 'user:1' in Redis?

You run the command: TYPE user:1. It returns the type of data stored at that key.

beginner

What type does Redis return if the key does not exist when using TYPE?

Redis returns 'none' if the key does not exist.

intermediate

List some common Redis data types that TYPE can return.

Common types are: string, list, set, zset (sorted set), hash, stream, and none.

intermediate

Why is it useful to check a key's type before performing operations in Redis?

Because Redis commands depend on the data type. Using the wrong command on a key type causes errors. TYPE helps avoid mistakes.

What does the Redis command TYPE mykey return if 'mykey' holds a list?

A list

B string

C set

D none

TYPE returns the exact data type stored at the key. For a list, it returns 'list'.

If you run TYPE on a key that does not exist, what is the result?

A none

B null

C error

D empty

Redis returns 'none' when the key does not exist.

Which Redis data type is NOT a possible TYPE command return value?

A hash

B queue

C zset

D stream

'queue' is not a Redis data type. TYPE returns known types like hash, zset, stream.

Why should you check a key's type before running commands on it?

A To avoid syntax errors

B To prevent data loss

C To avoid command errors due to wrong type

D To speed up Redis

Using commands on the wrong data type causes errors. TYPE helps prevent this.

What command would you use to find the type of key 'session:123'?

A GET session:123

B KEYS session:123

C EXISTS session:123

D TYPE session:123

TYPE command returns the data type of the key.

Explain how the TYPE command helps when working with Redis keys.

Think about why knowing the data type matters before using commands.

List the common Redis data types that the TYPE command can return and what 'none' means.

Recall the main Redis data structures and what happens if the key is not found.