> ## Documentation Index > Fetch the complete documentation index at: https://upstash.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Array commands > Commands for storing values in a sparse, index-addressed array. An array stores string values under unsigned integer indexes, from `0` up to `18446744073709551614`. It is sparse: an index either holds a value or is empty, and writing to a distant index does not allocate the slots in between. Nothing shifts when a value is deleted, so an index keeps its meaning for the lifetime of the key. That makes an array the right shape for data that already has a natural numeric key, such as a sequence number or a bucketed timestamp, where a [list](/docs/redis/commands/list/overview) would force a scan and a [hash](/docs/redis/commands/hash/overview) would store the index as a string. Two numbers describe an array and they are not the same. [`ARCOUNT`](/docs/redis/commands/array/arcount) is how many slots hold a value; [`ARLEN`](/docs/redis/commands/array/arlen) is the highest occupied index plus one. They agree only when the array is densely filled from `0`. Each array also keeps an append cursor, holding the index the last append wrote to. [`ARINSERT`](/docs/redis/commands/array/arinsert) appends after it, [`ARRING`](/docs/redis/commands/array/arring) appends after it and wraps within a fixed number of slots, [`ARNEXT`](/docs/redis/commands/array/arnext) reads where the next append will land, and [`ARSEEK`](/docs/redis/commands/array/arseek) moves it. The cursor tracks appends only: positional writes with [`ARSET`](/docs/redis/commands/array/arset) and deletions never move it, so a freed index is never silently reused. Set contiguous array values from an index Set values at several array indexes Get the value at an array index Get the values at several array indexes Get array values in an index range Scan the populated slots of an array Search array values with predicates Delete values at the given array indexes Delete array values in one or more index ranges Count the values stored in an array Get the length of an array Append values to an array Append values to a fixed-size ring Read the most recently written array values Get the index the next append will use Move the array append cursor Aggregate array values in an index range Inspect the internal layout of an array ## Related topics - [ARLEN](/docs/redis/commands/array/arlen.md) - [ARCOUNT](/docs/redis/commands/array/arcount.md) - [ARLASTITEMS](/docs/redis/commands/array/arlastitems.md) - [ARINFO](/docs/redis/commands/array/arinfo.md) - [ARGET](/docs/redis/commands/array/arget.md)