Version: latest

Boolean functions

not()#

  • parameters:
    • negand: boolean
  • result: boolean
not(true)
// false

is defined()#

Checks if a given value is defined or not. A value is defined if it exists, and it is an instance of one of the FEEL data types including null.

The function can be used to check if a variable, or a context entry (e.g. a property of a variable) exists. It allows differentiating between a variable that is null and a value that doesn't exist.

  • parameters:
    • value: any
  • result: boolean
is defined(1)
// true
is defined(null)
// true
is defined(x)
// false - if no variable "x" exists
is defined(x.y)
// false - if no variable "x" exists or it doesn't have a property "y"