Learn Advanced Array Methods by Building a Statistics Calculator - Step 32

Tell us what’s happening:

I think it should return true or false. But it does not pass the test

Your code so far

<!-- file: index.html -->
<!DOCTYPE html>
<html lang="en">
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" href="./styles.css" />
    <script src="./script.js"></script>
    <title>Statistics Calculator</title>
    <h1>Statistics Calculator</h1>
    <p>Enter a list of comma-separated numbers.</p>
    <form onsubmit="calculate(); return false;">
      <label for="numbers">Numbers:</label>
      <input type="text" name="numbers" id="numbers" />
      <button type="submit">Calculate</button>
    <div class="results">
        The <dfn>mean</dfn> of a list of numbers is the average, calculated by
        taking the sum of all numbers and dividing that by the count of numbers.
      <p class="bold">Mean: <span id="mean"></span></p>
        The <dfn>median</dfn> of a list of numbers is the number that appears in
        the middle of the list, when sorted from least to greatest.
      <p class="bold">Median: <span id="median"></span></p>
        The <dfn>mode</dfn> of a list of numbers is the number that appears most
        often in the list.
      <p class="bold">Mode: <span id="mode"></span></p>
        The <dfn>range</dfn> of a list of numbers is the difference between the
        largest and smallest numbers in the list.
      <p class="bold">Range: <span id="range"></span></p>
        The <dfn>variance</dfn> of a list of numbers measures how far the values
        are from the mean, on average.
      <p class="bold">Variance: <span id="variance"></span></p>
        The <dfn>standard deviation</dfn> of a list of numbers is the square
        root of the variance.
      <p class="bold">
        Standard Deviation: <span id="standardDeviation"></span>
/* file: styles.css */
body {
  margin: 0;
  background-color: rgb(27, 27, 50);
  text-align: center;
  color: #fff;

button {
  cursor: pointer;
  background-color: rgb(59, 59, 79);
  border: 3px solid white;
  color: white;

input {
  background-color: rgb(10, 10, 35);
  color: white;
  border: 1px solid rgb(59, 59, 79);

.bold {
  font-weight: bold;
/* file: script.js */
const getMean = (array) => array.reduce((acc, el) => acc + el, 0) / array.length;

const getMedian = (array) => {
  const sorted = array.sort((a, b) => a - b);
  const median =
    array.length % 2 === 0
      ? getMean([sorted[array.length / 2], sorted[array.length / 2 - 1]])
      : sorted[Math.floor(array.length / 2)];
  return median;

// User Editable Region

const getMode = (array) => {
  const counts = {};
  array.forEach((el) => {
    counts[el] = (counts[el] || 0) + 1;
  if (new Set(Object.values(counts)).size === 1) {
    return null;
  const highest = Object.keys(counts).sort(
    (a, b) => counts[b] - counts[a]
  const mode = Object.keys(counts).filter((el) => counts[el] === counts[hightest]? true : false);

// User Editable Region

const calculate = () => {
  const value = document.querySelector("#numbers").value;
  const array = value.split(/,\s*/g);
  const numbers = array.map(el => Number(el)).filter(el => !isNaN(el));
  const mean = getMean(numbers);
  const median = getMedian(numbers);

  document.querySelector("#mean").textContent = mean;
  document.querySelector("#median").textContent = median;

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/ Safari/537.36

Challenge Information:

Learn Advanced Array Methods by Building a Statistics Calculator - Step 32

1 Like

Good, but you don’t need a ternary operator to return the result of a comparison like this, it’s a bit redundant.


Your filter method is an arrow function that should implicitly return

1 Like

It is great that you solved the challenge, but instead of posting your full working solution, it is best to stay focused on answering the original poster’s question(s) and help guide them with hints and suggestions to solve their own issues with the challenge.

We are trying to cut back on the number of spoiler solutions found on the forum and instead focus on helping other campers with their questions and definitely not posting full working solutions.

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