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Co-authored-by: Naomi <nhcarrigan@gmail.com> Co-authored-by: Sem Bauke <semboot699@gmail.com>
5.2 KiB
5.2 KiB
id, title, challengeType, dashedName
| id | title | challengeType | dashedName |
|---|---|---|---|
| 6352f179bdca23221298a5ba | Step 43 | 0 | step-43 |
--description--
Your next calculation is the range, which is the difference between the largest and smallest numbers in the list.
You previously learned about the global Math object. Math has a .min() method to get the smallest number from a series of numbers, and the .max() method to get the largest number. Here's an example that gets the smallest number from an array:
const numbersArr = [2, 3, 1];
console.log(Math.min(...numbersArr));
// Expected output: 1
Declare a getRange function that takes the same array parameter you have been using. Using Math.min(), Math.max(), and the spread operator, return the difference between the largest and smallest numbers in the list.
--hints--
You should define a getRange function.
assert.isFunction(getRange);
Your getRange function should take an array parameter.
assert.match(getRange.toString(), /array/);
Your getRange function should use the spread operator on the array parameter.
assert.match(code.split("getRange")[1], /\.\.\.array/);
Your getRange function should use Math.max on the spread array parameter.
assert.match(code.split("getRange")[1], /Math\.max\(\s*\.\.\.array\s*\)/);
Your getRange function should use Math.min on the spread array parameter.
assert.match(code.split("getRange")[1], /Math\.min\(\s*\.\.\.array\s*\)/);
Your getRange function should return the difference between the largest and smallest numbers in the list.
assert.equal(getRange([1, 2, 3, 4, 5]), 4);
assert.equal(getRange([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]), 9);
--seed--
--seed-contents--
<!DOCTYPE html>
<html lang="en">
<head>
<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>
</head>
<body>
<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>
</form>
<div class="results">
<p>
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>
<p class="bold">Mean: <span id="mean"></span></p>
<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>
<p class="bold">Median: <span id="median"></span></p>
<p>
The <dfn>mode</dfn> of a list of numbers is the number that appears most
often in the list.
</p>
<p class="bold">Mode: <span id="mode"></span></p>
<p>
The <dfn>range</dfn> of a list of numbers is the difference between the
largest and smallest numbers in the list.
</p>
<p class="bold">Range: <span id="range"></span></p>
<p>
The <dfn>variance</dfn> of a list of numbers measures how far the values
are from the mean, on average.
</p>
<p class="bold">Variance: <span id="variance"></span></p>
<p>
The <dfn>standard deviation</dfn> of a list of numbers is the square
root of the variance.
</p>
<p class="bold">
Standard Deviation: <span id="standardDeviation"></span>
</p>
</div>
</body>
</html>
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;
}
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;
}
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]
)[0];
const mode = Object.keys(counts).filter(
(el) => counts[el] === counts[highest]
);
return mode.join(", ");
}
--fcc-editable-region--
--fcc-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);
const mode = getMode(numbers);
document.querySelector("#mean").textContent = mean;
document.querySelector("#median").textContent = median;
document.querySelector("#mode").textContent = mode;
}