131 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			131 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| id: 5d79253386060ed9eb04a070
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| title: Part 017
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| challengeType: 0
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| isBeta: true
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| ---
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| 
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| ## Description
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| <section id='description'>
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| 
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| The `match` parameter is currently unused, which can lead to unused variable warnings in some linters.
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| 
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| To fix this, prefix or replace it with an underscore (`_`) - both ways signal to the reader and linter that you're aware you don't need this.
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| 
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| Note that a single underscore can only be used once in a function and may conflict with some libraries (Lodash, Underscore.js).
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| 
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| </section>
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| 
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| ## Instructions
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| <section id='instructions'>
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| 
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| 
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| </section>
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| 
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| ## Tests
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| <section id='tests'>
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| 
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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("str.replace(regex,(_"));
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| 
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| ```
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| 
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| 
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| </section>
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| 
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| ## Challenge Seed
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| <section id='challengeSeed'>
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| 
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| <div id='html-seed'>
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| 
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| ```html
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| <script>
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| 
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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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| 
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| const infixEval = (str, regex) =>
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|   str.replace(regex, (match, arg1, fn, arg2) =>
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|     infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
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|   );
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| 
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| 
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| </script>
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| ```
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| 
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| </div>
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| 
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| 
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| ### Before Test
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| <div id='html-setup'>
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| 
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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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| 
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| </div>
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| 
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| 
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| ### After Test
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| <div id='html-teardown'>
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| 
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| ```html
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| </body>
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| </html>
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| ```
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| 
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| </div>
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| 
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| 
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| 
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| </section>
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| 
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| ## Solution
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| <section id='solution'>
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| 
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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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| 
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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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| </script>
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| ```
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| 
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| </section>
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