function that checks if a number is narcisstic or not

user_19376703 0
Viewed 49

I run the code multiple times but couldn't find the problem!!

A Narcissistic Number is a positive number which is the sum of its own digits, each raised to the power of the number of digits in a given base. In this Kata, we will restrict ourselves to decimal (base 10).

Your code must return true or false (not 'true' and 'false') depending upon whether the given number is a Narcissistic number in base 10.

function narcissistic(value) {
  let strDigits = value.toString();
  let power = strDigits.length;
  
  let arrayDigits = strDigits.split('');
  let sum, poweredValue = 0;
  for (let i = 0; i < power; i++){
   poweredValue = Number(arrayDigits[i])**power;
    sum += poweredValue;
  }
  if (sum === value){
    return true;
  }else {
    return false;
  }
  };

javascript
3 Answers

You have to assign the initial value for sum as 0. By default, it's set to undefined. And adding something to undefined gives NaN, and any comparison with NaN is always false.

function narcissistic(value) {
  let strDigits = value.toString();
  let power = strDigits.length;

  let arrayDigits = strDigits.split("");
  let sum = 0,
    poweredValue = 0;
  for (let i = 0; i < power; i++) {
    poweredValue = Number(arrayDigits[i]) ** power;
    sum += poweredValue;
  }
  if (sum === value) {
    return true;
  } else {
    return false;
  }
}
user_95490120

You assumed that the statement of the form:

let x, y =0;

initialize x and y both as 0. But x is still undefined. And type undefined + type number will evaluate to NaN (not a number). And no number is equal to NaN

Just initialize properly:

function narcissistic(value) {
  let strDigits = value.toString();
  let power = strDigits.length;
  let arrayDigits = strDigits.split('');
  let sum =0, poweredValue = 0;
  for (let i = 0; i < power; i++){
   poweredValue = Number(arrayDigits[i])**power;
    sum += poweredValue;
  }
  if (sum === value){
    return true;
  }else {
    return false;
  }
  };
  
  
  console.log(narcissistic(153));

user_101401240

Something like that?

const n = 153

function action(n) {
  let sum = 0;
  n.toString().split('').forEach(i => {
    sum += parseInt(i)**n.toString().length;  
  })
  return sum == n  
}

console.log(action(n))

user_148071110
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