84 lines
2.5 KiB
Markdown
84 lines
2.5 KiB
Markdown
---
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id: 587d7dab367417b2b2512b6d
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title: Apply Functional Programming to Convert Strings to URL Slugs
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challengeType: 1
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forumTopicId: 301227
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---
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# --description--
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The last several challenges covered a number of useful array and string methods that follow functional programming principles. We've also learned about `reduce`, which is a powerful method used to reduce problems to simpler forms. From computing averages to sorting, any array operation can be achieved by applying it. Recall that `map` and `filter` are special cases of `reduce`.
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Let's combine what we've learned to solve a practical problem.
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Many content management sites (CMS) have the titles of a post added to part of the URL for simple bookmarking purposes. For example, if you write a Medium post titled "Stop Using Reduce", it's likely the URL would have some form of the title string in it (".../stop-using-reduce"). You may have already noticed this on the freeCodeCamp site.
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# --instructions--
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Fill in the `urlSlug` function so it converts a string `title` and returns the hyphenated version for the URL. You can use any of the methods covered in this section, and don't use `replace`. Here are the requirements:
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The input is a string with spaces and title-cased words
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The output is a string with the spaces between words replaced by a hyphen (`-`)
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The output should be all lower-cased letters
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The output should not have any spaces
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# --hints--
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Your code should not use the `replace` method for this challenge.
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```js
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assert(!code.match(/\.?[\s\S]*?replace/g));
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```
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`urlSlug("Winter Is Coming")` should return `"winter-is-coming"`.
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```js
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assert(urlSlug('Winter Is Coming') === 'winter-is-coming');
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```
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`urlSlug(" Winter Is Coming")` should return `"winter-is-coming"`.
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```js
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assert(urlSlug(' Winter Is Coming') === 'winter-is-coming');
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```
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`urlSlug("A Mind Needs Books Like A Sword Needs A Whetstone")` should return `"a-mind-needs-books-like-a-sword-needs-a-whetstone"`.
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```js
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assert(
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urlSlug('A Mind Needs Books Like A Sword Needs A Whetstone') ===
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'a-mind-needs-books-like-a-sword-needs-a-whetstone'
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);
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```
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`urlSlug("Hold The Door")` should return `"hold-the-door"`.
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```js
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assert(urlSlug('Hold The Door') === 'hold-the-door');
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```
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# --seed--
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## --seed-contents--
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```js
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// Only change code below this line
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function urlSlug(title) {
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}
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// Only change code above this line
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```
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# --solutions--
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```js
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// Only change code below this line
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function urlSlug(title) {
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return title.trim().split(/\s+/).join("-").toLowerCase();
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}
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```
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