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Function: binary()

binary<A, B, R>(fn): (a, b) => R

Defined in: function/arity/index.ts:70

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

This is useful when you want to limit the number of arguments passed to a function in callbacks or higher-order functions.

Type Parameters​

A​

A

B​

B

R​

R

Parameters​

fn​

(a, b, ...rest) => R

Returns​

(a, b): R

Parameters​

a​

A

b​

B

Returns​

R

Examples​

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

add(1, 2, 3, 4)           // => 10
binary(add)(1, 2, 3, 4)   // => 3 (only uses first two)
// Limiting callback arguments
const logTwo = binary(console.log)

['a', 'b', 'c'].forEach(logTwo)
// Logs:
// a 0
// b 1
// c 2
// (ignores array parameter)