Boolean functions

not(negand)

Returns the logical negation of the given value.

Function signature

not(negand: boolean): boolean

Examples

not(true)
// false

not(null)
// null

is defined(value)

Camunda Extension

Checks if a given value is defined. 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 null variable and a value that doesn't exist.

Function signature

is defined(value: Any): boolean

Examples

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"