Intro to Variables

App Variables

Variables that can be set and used throughout your entire application.

Each time your app restarts, this type of variable will reset to its default value.

Useful for storing constants as a default value or other app-wide, non-user-specific, data such as an error_message or to store the state of a Modal.

Device Variables

Variables that allow you to store data on your app users' devices that can be used throughout your app.

Each time your app restarts, this type of variable will not reset to the default value and will use the last value stored in it.

Useful for storing user-specific data that needs to persist across sessions, such as an auth_token after login.

Screen Variables

Variables that are scoped to the Screen on which they are created.

Each time the app restarts or the Screen is removed from the navigation stack, this value will be reset to its default value.

Useful for storing Screen-specific data, such as variables associated with various input components for a form.

System Variables

System-generated variables that come with a pre-defined value such as Is Online, Is iOS, and Device Width.

String

"Hello World"

Number

99 3.33

Boolean

true false

Object

{"name": "Dave"} {"address": {"city": "Austin", "state": "Texas"}}

Array

[1, 2, 3] ["violet", "indigo"] [{"name": "Dave"}, {"name": "Rahul"}]