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5.5 KiB
5.5 KiB
id, title, challengeType, dashedName
| id | title | challengeType | dashedName |
|---|---|---|---|
| 646d48b936802fd34c3f05af | Step 97 | 0 | step-97 |
--description--
Your spreadsheet is now functional. However, you don't have support for very many formulas.
Add an even property to your spreadsheetFunctions. It should take a nums parameter, and return the result of filtering the nums array to only include even numbers. Use a reference to your isEven function to help.
--hints--
Your spreadsheetFunctions object should have an even property.
assert.property(spreadsheetFunctions, "even");
Your even property should be a function.
assert.isFunction(spreadsheetFunctions.even);
Your even function should take a nums parameter.
assert.match(code, /even\s*:\s*(\(\s*nums\s*\)|nums)\s*=>/)
Your even function should use an implicit return.
assert.notMatch(code, /even\s*:\s*(\(\s*nums\s*\)|nums)\s*=>\s*\{/)
Your even function should return the result of calling the .filter() method on nums.
assert.match(code, /even\s*:\s*(\(\s*nums\s*\)|nums)\s*=>\s*nums\s*\.\s*filter/)
You should pass a reference to your isEven() function as the callback for the .filter() method.
assert.match(code, /even\s*:\s*(\(\s*nums\s*\)|nums)\s*=>\s*nums\s*\.\s*filter\s*\(\s*isEven\s*\)/)
Your even function should return an array of even numbers.
assert.deepEqual(spreadsheetFunctions.even([1, 2, 3, 4, 5, 6]), [2, 4, 6]);
--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" />
<title>Functional Programming Spreadsheet</title>
</head>
<body>
<div id="container">
<div></div>
</div>
<script src="./script.js"></script>
</body>
</html>
#container {
display: grid;
grid-template-columns: 50px repeat(10, 200px);
grid-template-rows: repeat(11, 30px);
}
.label {
background-color: lightgray;
text-align: center;
vertical-align: middle;
line-height: 30px;
}
const infixToFunction = {
"+": (x, y) => x + y,
"-": (x, y) => x - y,
"*": (x, y) => x * y,
"/": (x, y) => x / y,
}
const infixEval = (str, regex) => str.replace(regex, (_match, arg1, operator, arg2) => infixToFunction[operator](parseFloat(arg1), parseFloat(arg2)));
const highPrecedence = str => {
const regex = /([\d.]+)([*\/])([\d.]+)/;
const str2 = infixEval(str, regex);
return str === str2 ? str : highPrecedence(str2);
}
const isEven = num => num % 2 === 0;
const sum = nums => nums.reduce((acc, el) => acc + el, 0);
const average = nums => sum(nums) / nums.length;
const median = nums => {
const sorted = nums.slice().sort((a, b) => a - b);
const length = sorted.length;
const middle = length / 2 - 1;
return isEven(length)
? average([sorted[middle], sorted[middle + 1]])
: sorted[Math.ceil(middle)];
}
--fcc-editable-region--
const spreadsheetFunctions = {
sum,
average,
median,
}
--fcc-editable-region--
const applyFunction = str => {
const noHigh = highPrecedence(str);
const infix = /([\d.]+)([+-])([\d.]+)/;
const str2 = infixEval(noHigh, infix);
const functionCall = /([a-z0-9]*)\(([0-9., ]*)\)(?!.*\()/i;
const toNumberList = args => args.split(",").map(parseFloat);
const apply = (fn, args) => spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
return str2.replace(functionCall, (match, fn, args) => spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? apply(fn, args) : match);
}
const range = (start, end) => Array(end - start + 1).fill(start).map((element, index) => element + index);
const charRange = (start, end) => range(start.charCodeAt(0), end.charCodeAt(0)).map(code => String.fromCharCode(code));
const evalFormula = (x, cells) => {
const idToText = id => cells.find(cell => cell.id === id).value;
const rangeRegex = /([A-J])([1-9][0-9]?):([A-J])([1-9][0-9]?)/gi;
const rangeFromString = (num1, num2) => range(parseInt(num1), parseInt(num2));
const elemValue = num => character => idToText(character + num);
const addCharacters = character1 => character2 => num => charRange(character1, character2).map(elemValue(num));
const rangeExpanded = x.replace(rangeRegex, (_match, char1, num1, char2, num2) => rangeFromString(num1, num2).map(addCharacters(char1)(char2)));
const cellRegex = /[A-J][1-9][0-9]?/gi;
const cellExpanded = rangeExpanded.replace(cellRegex, match => idToText(match.toUpperCase()));
const functionExpanded = applyFunction(cellExpanded);
return functionExpanded === x ? functionExpanded : evalFormula(functionExpanded, cells);
}
window.onload = () => {
const container = document.getElementById("container");
const createLabel = (name) => {
const label = document.createElement("div");
label.className = "label";
label.textContent = name;
container.appendChild(label);
}
const letters = charRange("A", "J");
letters.forEach(createLabel);
range(1, 99).forEach(number => {
createLabel(number);
letters.forEach(letter => {
const input = document.createElement("input");
input.type = "text";
input.id = letter + number;
input.ariaLabel = letter + number;
input.onchange = update;
container.appendChild(input);
})
})
}
const update = event => {
const element = event.target;
const value = element.value.replace(/\s/g, "");
if (!value.includes(element.id) && value.startsWith('=')) {
element.value = evalFormula(value.slice(1), Array.from(document.getElementById("container").children));
}
}