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STRLEN

Returns the length of the string stored at a key.

Syntax​

STRLEN key

Parameters​

  • key: The name of the key whose string length you want to retrieve.

Details​

  • Available since: 2.2.0
  • Time complexity: O(1)
  • ACL categories: @read, @string, @fast

The STRLEN command returns the length of the string value stored at the specified key. If the key does not exist, STRLEN returns 0. This command is useful for quickly determining the size of a string stored at a particular key.

Examples​

Basic Usage​

Assume we have a key called mykey with the value "Hello, World!":

SET mykey "Hello, World!"

To retrieve the length of the string stored in mykey:

STRLEN mykey

This will return:

(integer) 13

The length of "Hello, World!" is 13 characters.

Handling a Non-Existent Key​

If you try to get the length of a key that does not exist:

STRLEN nonexistingkey

This will return:

(integer) 0

Edge Cases​

  • If the key does not exist, STRLEN returns 0.
  • If the key exists but does not hold a string value, an error is returned.

RESP2/RESP3 Reply​

  • Integer reply: the length of the string at the specified key.