armstrong_numbers.clj

(defn armstrong? [n]
  (let [n-chars (apply vector (str n))]
    (= n
       (int
        (reduce +
                (map
                 (comp
                  #(Math/pow % (count n-chars))
                  #(Character/getNumericValue %))
                 n-chars))))))

armstrong_numbers.js

function isArmstrong(number) {
  const numberDigits = Array.from(number.toString()).map(parseInt)
  const sumPowers = numberDigits
    .map(digit => Math.pow(digit, numberDigits.length))
    .reduce((a, b) => a + b, 0)
  return sumPowers === number
}

armstrong_numbers.py

def is_armstrong(number):
  number_str = str(number)
  return sum(int(char)**len(number_str) for char in number_str) == number

armstrong_numbers.sc

def isArmstrong(number: Int) = {
  val numberDigits = number.toString.map(Character.getNumericValue)
  number == numberDigits.map(Math.pow(_, numberDigits.length)).sum
}