The concept of

compose

is simple — it combines n functions. It’s a pipe flowing right-to-left, calling each function with the output of the last one.

Array.prototype.reduceRight = function (...args) {
  const _this = this
  return _this.reverse().reduce(...args)
}

const compose = (...args) => x => args.reduceRight((acc, currFn)=>{
return currFn(acc)
}, x)


const double = x => x * 2
const inc = x => x + 1


const incAndOct = compose(double, double, double, inc)

incAndOct(2) //24

Explanation:

we are passing

2

to

incAndOct

function. First it will call

inc

method then the result will be

3

and next it will apply double method on

3

so result is

6

again one more double but this time on

double(3)

i.e

6

result is 12 now final double on

12

it is

24