Data Structures Overview

This page provides an overview of the core data structures in q, including their structure, dimensions, and typical usage.

In q, the following data structures exist:

Name	Dimension	Definition	Example
Atom	1x1	A single, indivisible value of a specific type.	3.14
List/Array	n x 1	An ordered, zero-indexed sequence of values, which can be uniform or mixed type.	1 2 3
Dictionary	n x 2	A key-value mapping that associates a list of keys with a list of values.	("Alice; "Bob"; "Mike")!30 25 43
Table	n x m	A collection of named, equal-length columns stored as a flipped dictionary.	([] name:`Alice`Bob; age:30 25)
Keyed Table	(n x k) + (n x m)	A dictionary mapping a table of key columns to a table of value columns.	([id:1 2] name:`Alice`Bob; age:30 25)