LRANGE for reading elements in Redis

Introduction

LRANGE helps you get a part or all of a list stored in Redis. It is like reading a few pages from a book instead of the whole book.

You want to see the first few items in a list of recent messages.

You need to get the last 10 scores from a game leaderboard.

You want to read a specific range of elements from a list of tasks.

You want to display a page of comments from a long list.

Syntax

Redis

LRANGE key start stop

start and stop are indexes, starting at 0 for the first element.

Use -1 to mean the last element, -2 for the second last, and so on.

Examples

Gets the first three elements (index 0 to 2) from the list named 'mylist'.

Redis

LRANGE mylist 0 2

Gets all elements from the list 'mylist'.

Redis

LRANGE mylist 0 -1

Gets the last three elements from the list 'mylist'.

Redis

LRANGE mylist -3 -1

Sample Program

First, we add five fruits to 'mylist'. Then, we get elements from index 1 to 3, which are the second to fourth fruits.

Redis

RPUSH mylist "apple" "banana" "cherry" "date" "elderberry"
LRANGE mylist 1 3

Important Notes

Indexes are inclusive, so both start and stop elements are included in the result.

If start is greater than the last index, the result is empty.

If stop is greater than the last index, it stops at the last element.

Summary

LRANGE reads a part or all of a Redis list by index range.

Indexes start at 0 and can be negative to count from the end.

It returns the elements between start and stop, including both.