spliter

function spliter(n) {
  const arr = []

  return function(str) {
   const x = (str.length / n).toFixed()
   let m = n

   for (let i = 0; i < str.length; i = i + n ) {
     let y = str.slice(i, m)
     arr.push(y)
     console.log(i, m)
     m+=n
   }

   return arr
  }
}

let x = '123456789'

console.log(spliter(3)('12345678910123'))