AEL (Expression language) was created to process data and turn it into presentable responses that will be valuable to the bot's users. This data can be obtained in different ways: it can be a result of NLU recognition (an intent or a variable), a response from an API integration, or a value previously stored in Memory.

Each piece of such data has its own type.

Each type of data has its own purpose and its own methods that can be used to process it. For example, any plain text will have a data type of string so you can perform operations relevant to texts (like joining them together), and any number will have a data type of number so you can, for example, perform arithmetical operations on them.

List of data types in AEL

Data type	Example	Short description	More info and methods
String	`"Hello, I'm SentiBot."`	Plain text/any sequence of characters.	Strings page
Number	`23`	Any sequence of digits and decimal points representing a number.	Numbers page
Array	`["Jim", "Dwight", "Michael"]`	An ordered list of elements. An element can be of any data type.	Arrays page
Object	`{"name": "Jim", "age": 33}`	A set of one or multiple key-value pairs called "properties".	Objects page
DateTime	`2023-05-18T12:00`	A value respresenting date and time.	DateTime API page
Boolean	`true` or `false`	Always one of the two truth values: `true` or `false`.	-
Null	`null`	An intentional absence of a value or an undefined value.	-