175 lines
3.4 KiB
Markdown
175 lines
3.4 KiB
Markdown
---
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id: 5d792534408c5be896b0a46e
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title: Part 037
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challengeType: 0
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isBeta: true
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---
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## Description
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<section id='description'>
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The `hasOwnProperty` method checks if a key exists in an object. So `spreadsheetFunctions.hasOwnProperty("")` would return `true`, but replacing `""` with anything else would make it return `false`.
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Chain `hasOwnProperty` to `spreadsheetFunctions` to check if the `fn.toLowerCase()` key exists in `spreadsheetFunctions`.
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: See description above for instructions.
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testString: assert(code.replace(/\s/g, "").includes("returnstr2.replace(regex,(match,fn,args)=>spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()))"));
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='html-seed'>
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```html
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<script>
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const infixToFunction = {
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"+": (x, y) => x + y,
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"-": (x, y) => x - y,
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"*": (x, y) => x * y,
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"/": (x, y) => x / y
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};
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const infixEval = (str, regex) =>
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str.replace(regex, (_, arg1, fn, arg2) =>
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infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
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);
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const highPrecedence = str => {
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const regex = /([0-9.]+)([*\/])([0-9.]+)/;
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const str2 = infixEval(str, regex);
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return str === str2 ? str : highPrecedence(str2);
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};
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const spreadsheetFunctions = {
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"": x => x
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};
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const applyFn = str => {
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const noHigh = highPrecedence(str);
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const infix = /([0-9.]+)([+-])([0-9.]+)/;
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const str2 = infixEval(noHigh, infix);
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const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
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const toNumberList = args => args.split(",").map(parseFloat);
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const applyFunction = (fn, args) =>
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spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
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return str2.replace(regex, (match, fn, args) => spreadsheetFunctions);
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}
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</script>
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```
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</div>
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### Before Test
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<div id='html-setup'>
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```html
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<title>Spreadsheet</title>
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<style>
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#container {
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display: grid;
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grid-template-columns: 50px repeat(10, 200px);
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grid-template-rows: repeat(11, 30px);
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}
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.label {
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background-color: lightgray;
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text-align: center;
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vertical-align: middle;
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line-height: 30px;
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}
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</style>
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</head>
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<body>
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<div id="container">
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<div></div>
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</div>
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```
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</div>
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### After Test
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<div id='html-teardown'>
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```html
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</body>
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</html>
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```html
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<script>
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const infixToFunction = {
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"+": (x, y) => x + y,
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"-": (x, y) => x - y,
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"*": (x, y) => x * y,
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"/": (x, y) => x / y
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};
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const infixEval = (str, regex) =>
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str.replace(regex, (_, arg1, fn, arg2) =>
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infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
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);
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const highPrecedence = str => {
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const regex = /([0-9.]+)([*\/])([0-9.]+)/;
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const str2 = infixEval(str, regex);
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return str === str2 ? str : highPrecedence(str2);
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};
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const spreadsheetFunctions = {
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"": x => x
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};
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const applyFn = str => {
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const noHigh = highPrecedence(str);
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const infix = /([0-9.]+)([+-])([0-9.]+)/;
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const str2 = infixEval(noHigh, infix);
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const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
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const toNumberList = args => args.split(",").map(parseFloat);
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const applyFunction = (fn, args) =>
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spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
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return str2.replace(
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regex,
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(match, fn, args) =>
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spreadsheetFunctions.hasOwnProperty(fn.toLowerCase())
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);
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}
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</script>
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```
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</section>
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