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Function: nAry()

nAry<R>(n, fn): (...args) => R

Defined in: function/arity/index.ts:114

Creates a function that only accepts N arguments, ignoring additional arguments.

This is the generalized version of unary and binary, allowing you to specify exactly how many arguments should be accepted.

Type Parameters​

R​

R

Parameters​

n​

number

fn​

(...args) => R

Returns​

(...args): R

Parameters​

args​

...any[]

Returns​

R

Examples​

const sum = (...nums: number[]) => nums.reduce((a, b) => a + b, 0)

const sumTwo = nAry(2, sum)
sumTwo(1, 2, 3, 4, 5)  // => 3 (only sums first two)

const sumThree = nAry(3, sum)
sumThree(1, 2, 3, 4, 5)  // => 6 (only sums first three)
// Controlling variadic functions
const max = (...nums: number[]) => Math.max(...nums)

const maxOfTwo = nAry(2, max)
maxOfTwo(5, 10, 2, 8)  // => 10 (only considers first two)
// Creating specialized versions
const log = (...args: any[]) => console.log(...args)

const logOne = nAry(1, log)
const logThree = nAry(3, log)

logOne('a', 'b', 'c')      // Logs: a
logThree('a', 'b', 'c', 'd')  // Logs: a b c