2019-11-05 02:09:40 -01:00
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---
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id: 5d792533ed00e75d129e1b18
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2020-08-25 02:19:45 -07:00
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title: Part 13
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2019-11-05 02:09:40 -01:00
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challengeType: 0
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---
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## Description
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<section id='description'>
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`replace` is a higher order function because it can take a function as argument (higher order functions can also return functions).
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2019-12-09 19:37:02 +09:00
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Pass the `+` function from `infixToFunction` to the `replace` method as the second argument.
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2019-11-05 02:09:40 -01:00
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This is how you would pass the `-` function:
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```js
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str.replace(regex, infixToFunction["-"])
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```
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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(infixEval("ab", /(a)b/) === "aba");
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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) => str.replace(regex, "");
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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) => str.replace(regex, infixToFunction["+"]);
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</script>
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```
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</section>
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