3.9 KiB
id, title, challengeType, dashedName
| id | title | challengeType | dashedName |
|---|---|---|---|
| 63507e4562cdde3a28e8de1b | Step 7 | 0 | step-7 |
--description--
Much like the .map() method, the .filter() method takes a callback function. The callback function takes the current element as its first argument.
array.filter(el => {
})
The callback function needs to return a Boolean value, which indicates whether the element should be included in the new array. In this case, you want to return true if the element is not NaN (not a number).
However, you cannot check for equality here, because NaN is not equal to itself. Instead, you can use the isNaN() method, which returns true if the argument is NaN.
Add a callback function to your .filter() method that returns true if the element is not NaN.
--hints--
Your .filter() method should have a callback which accepts el as a parameter.
assert.match(calculate.toString(), /numbers\.filter\(\s*(\(\s*el\s*\)|el)\s*=>|numbers\.filter\(\s*function\s*\(\s*el\s*\)\s*\{/)
Your callback function should use ! and isNaN() to check if el is NOT NaN.
assert.match(calculate.toString(), /!\s*(Number\.)?isNaN\(\s*el\s*\)/);
Your callback function should return elements that are not NaN.
assert.match(calculate.toString(), /(numbers\.filter\(\s*(\(\s*el\s*\)|el)\s*=>|numbers\.filter\(\s*function\s*\(\s*el\s*\)\s*\{)\s*(return\s*)?!(Number\.)?isNaN\(\s*el\s*\)/);
--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();
}
--fcc-editable-region--