RPOP

Syntax

RPOP key [count]

Description

The RPOP command removes and returns elements from the right (tail) of a list. If a count is specified, multiple elements are removed and returned. If the key does not exist, an empty array is returned.

Arguments

• key (required): The name of the list key.
• count (optional): The number of elements to pop. If not specified, defaults to 1. Must be a positive integer.

Return Value

Returns an Array:

• An array of popped elements (in reverse order - last element first)
• An empty array if the key doesn't exist or the list is empty

Examples

Popping a Single Element

RPUSH mylist "a" "b" "c"
RPOP mylist

Response:

(integer) 3
"c"

Popping Multiple Elements

RPUSH mylist "a" "b" "c" "d"
RPOP mylist 2

Response:

(integer) 4
1) "d"
2) "c"

Note: Elements are returned in reverse order (last element first).

Popping from Empty List

RPOP emptylist

Response:

(nil)

Popping More Than Available

RPUSH mylist "a" "b"
RPOP mylist 5

Response:

(integer) 2
1) "b"
2) "a"

Note: If you request more elements than are available, all available elements are returned.

Notes

• Elements are removed from the right (tail) of the list
• Returns elements in reverse order (last element first)
• If count is greater than the list length, all elements are returned
• Returns an empty array if the key doesn't exist
• Returns a WRONGTYPE error if the key exists but is not a list

Use Cases

• Queues: Implement FIFO (First In, First Out) operations
• Task Processing: Remove tasks from the end of a queue
• Message Processing: Process messages from the tail of a queue
• Stack Operations: Use as a stack (with RPUSH/RPOP)

Related Commands

• LPOP - Remove and return elements from the left
• RPUSH - Append values to a list
• LRANGE - Get a range of elements from a list