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Boolean Functions

Last updated June 16, 2026, 1:07 PM UTC · fuuz.com/help/boolean-functions

Standard JSONata Boolean functions available in expressions throughout the Fuuz platform.

$boolean()

Signature: $boolean(arg)

Casts the argument to a Boolean using the following rules:

Argument type Result
Boolean unchanged
string: empty false
string: non-empty true
number: 0 false
number: non-zero true
null false
array: empty false
array: contains a member that casts to true true
array: all members cast to false false
object: empty false
object: non-empty true
function false

$not()

Signature: $not(arg)

Returns Boolean NOT on the argument. arg is first cast to a Boolean.

$exists()

Signature: $exists(arg)

Returns Boolean true if the arg expression evaluates to a value, or false if the expression does not match anything (e.g. a path to a non-existent field reference).

See Also