KeyFreeQ

KeyFreeQ[assoc,form]

yields True if no key in the association assoc matches form, and yields False otherwise.

KeyFreeQ[form]

represents an operator form of KeyFreeQ that can be applied to an expression.

Examples

Basic Examples  (4)

Test whether "foo" is a key in the association:

Test whether the association contains a string key:

KeyFreeQ works with lists of rules:

Determine which of the associations does not contain the key:

Introduced in 2015
 (10.3)