The [[Arity]] of some [[Function]], [[Operation]] or [[Relation]] $f$ is the number of operands / arguments for $f$. A common example is a [[Binary Operation]], which has an arity of 2 as it maps two argument to a result. >[!example] Example: >A function $f$ with arity 1: >$f(x) = 2x$ >[!example] Example: Javascript function [[Arity]] 3 >```js >function f(x, y, z) { > return x + y + z; >} >```