Arity
/ˈær.ɪ.ti/ · Noun · Development
Definitions
The number of arguments or operands that a function, operator, or constructor accepts. A unary function has arity 1, a binary function arity 2, and so on.
In plain English: How many inputs a function takes — for example, a function that adds two numbers has an arity of 2.
Example: "In Erlang, functions are identified by name and arity, so add/2 and add/3 are completely different functions."