LRANGE

Syntax

LRANGE key start stop

Description

The LRANGE command returns the specified range of elements from a list. The range is specified by two indices: start and stop. Both indices are zero-based, and negative indices can be used to count from the end of the list.

Arguments

• key (required): The name of the list key.
• start (required): The starting index (0-based). Negative values count from the end (-1 is the last element).
• stop (required): The ending index (inclusive). Negative values count from the end (-1 is the last element).

Return Value

Returns an Array: A list of elements in the specified range, or an empty array if the key doesn't exist or the range is invalid.

Index Behavior

• Positive indices: Count from the beginning (0 is the first element)
• Negative indices: Count from the end (-1 is the last element)
• Range: Both start and stop are inclusive
• Out of bounds: Automatically adjusted to valid range

Examples

Getting All Elements

RPUSH mylist "a" "b" "c" "d" "e"
LRANGE mylist 0 -1

Response:

(integer) 5
1) "a"
2) "b"
3) "c"
4) "d"
5) "e"

Getting First Three Elements

LRANGE mylist 0 2

Response:

1) "a"
2) "b"
3) "c"

Getting Last Two Elements

LRANGE mylist -2 -1

Response:

1) "d"
2) "e"

Using Negative Indices

LRANGE mylist -3 -1

Response:

1) "c"
2) "d"
3) "e"

Getting Middle Elements

LRANGE mylist 1 3

Response:

1) "b"
2) "c"
3) "d"

Empty Range

LRANGE mylist 5 10

Response:

(empty array)

Non-Existent Key

LRANGE nonexistent 0 -1

Response:

(empty array)

Special Cases

start Greater Than stop

If start is greater than stop, an empty array is returned:

LRANGE mylist 3 1

Response:

(empty array)

Out of Bounds Indices

Indices are automatically adjusted:

• If start is negative and beyond the beginning, it's set to 0
• If stop is beyond the end, it's set to the last index

LRANGE mylist -10 10

Response:

1) "a"
2) "b"
3) "c"
4) "d"
5) "e"

Notes

• Both start and stop are inclusive
• Negative indices count from the end (-1 is the last element)
• Returns an empty array if the key doesn't exist
• Returns a WRONGTYPE error if the key exists but is not a list
• The range is automatically adjusted to valid bounds

Use Cases

• Viewing Lists: Display all or part of a list
• Pagination: Get a page of items from a list
• Recent Items: Get the last N items from a list
• Data Inspection: Examine list contents for debugging

Related Commands

• LPUSH - Prepend values to a list
• RPUSH - Append values to a list
• LLEN - Get the length of a list