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3.8 KiB
3.8 KiB
id, title, challengeType, dashedName
| id | title | challengeType | dashedName |
|---|---|---|---|
| 63507ebb0c50ce3b9d669cd9 | Step 8 | 0 | step-8 |
--description--
Array methods can often be chained together to perform multiple operations at once. As an example:
array.map().filter();
The .map() method is called on the array, and then the .filter() method is called on the result of the .map() method. This is called method chaining.
Following that example, remove your filtered variable, and chain your .filter() call to your .map() call above. Do not remove either of the callback functions.
--hints--
You should remove the filtered variable.
assert.notMatch(calculate.toString(), /filtered/);
You should chain your .filter() call to your .map() call.
assert.match(calculate.toString(), /array\.map\(.*\)\.filter\(/s);
You should not remove the .map() callback.
assert.match(calculate.toString(), /(array\.map\(\s*(\(\s*el\s*\)|el)\s*=>|array\.map\(\s*function\s*\(\s*el\s*\)\s*\{)\s*(return\s+)?Number\(\s*el\s*\)/);
You should not remove the .filter() callback.
assert.match(calculate.toString(), /(\.filter\(\s*(\(\s*el\s*\)|el)\s*=>|\.filter\(\s*function\s*\(\s*el\s*\)\s*\{)\s*(return\s*)?!(Number\.)?isNaN\(\s*el\s*\)/s);
--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();">
<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;
}
--fcc-editable-region--
const calculate = () => {
const value = document.querySelector("#numbers").value;
const array = value.split(/,\s*/g);
const numbers = array.map(el => Number(el));
const filtered = numbers.filter(el => !isNaN(el));
}
--fcc-editable-region--