59 lines
2.1 KiB
Markdown
59 lines
2.1 KiB
Markdown
---
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id: 587d7db6367417b2b2512b9b
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title: Find Characters with Lazy Matching
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challengeType: 1
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---
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## Description
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<section id='description'>
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In regular expressions, a <code>greedy</code> match finds the longest possible part of a string that fits the regex pattern and returns it as a match. The alternative is called a <code>lazy</code> match, which finds the smallest possible part of the string that satisfies the regex pattern.
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You can apply the regex <code>/t[a-z]*i/</code> to the string <code>"titanic"</code>. This regex is basically a pattern that starts with <code>t</code>, ends with <code>i</code>, and has some letters in between.
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Regular expressions are by default <code>greedy</code>, so the match would return <code>["titani"]</code>. It finds the largest sub-string possible to fit the pattern.
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However, you can use the <code>?</code> character to change it to <code>lazy</code> matching. <code>"titanic"</code> matched against the adjusted regex of <code>/t[a-z]*?i/</code> returns <code>["ti"]</code>.
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<strong>Note</strong><br>Parsing HTML with regular expressions should be avoided, but pattern matching an HTML string with regular expressions is completely fine.
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</section>
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## Instructions
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<section id='instructions'>
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Fix the regex <code>/<.*>/</code> to return the HTML tag <code><h1></code> and not the text <code>"<h1>Winter is coming</h1>"</code>. Remember the wildcard <code>.</code> in a regular expression matches any character.
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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: The <code>result</code> variable should be an array with <code><h1></code> in it
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testString: assert(result[0] == '<h1>', 'The <code>result</code> variable should be an array with <code><h1></code> in it');
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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='js-seed'>
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```js
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let text = "<h1>Winter is coming</h1>";
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let myRegex = /<.*>/; // Change this line
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let result = text.match(myRegex);
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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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```js
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let text = "<h1>Winter is coming</h1>";
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let myRegex = /<.*?>/; // Change this line
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let result = text.match(myRegex);
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```
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</section>
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