68 lines
4.1 KiB
Markdown
68 lines
4.1 KiB
Markdown
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---
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title: Write Higher Order Arrow Functions
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---
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 Remember to use <a>**`Read-Search-Ask`**</a> if you get stuck. Try to pair program  and write your own code 
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### Problem Explanation:
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We need to compute and square values from the `realNumberArray` and store them in the variable `squaredIntegers` using the `map()`, `filter()`, and/or `reduce()` functions.
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##  Hint: 1
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* You will need to `filter()` the `realNumberArray` for positive integers (decimals are not integers).
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> _try to solve the problem now_
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##  Hint: 2
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* You will need to `map()` the values from your `filter()` function to the variable `squaredIntegers`.
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> _try to solve the problem now_
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##  Hint: 3
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* Remember the magic of chaining functions.
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> _try to solve the problem now_
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## Spoiler Alert!
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**Solution ahead!**
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##  Basic Code Solution:
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```javascript
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const squareList = (arr) => {
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"use strict";
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const squaredIntegers = arr.filter( (num) => num > 0 && num % parseInt(num) === 0 ).map( (num) => Math.pow(num, 2) );
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return squaredIntegers;
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};
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// test your code
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const squaredIntegers = squareList(realNumberArray);
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console.log(squaredIntegers);
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```
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 <a href='https://codepen.io/dylantyates/pen/WyWoYJ' target='_blank' rel='nofollow'>Run Code</a>
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# Code Explanation:
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Uses the operator `filter()` and `map()` functions to square all positive integers in a given array.
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#### Relevant Links
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* <a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map' target='_blank' rel='nofollow'>map()</a>
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* <a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter' target='_blank' rel='nofollow'>filter()</a>
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* <a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce' target='_blank' rel='nofollow'>reduce()</a>
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##  NOTES FOR CONTRIBUTIONS:
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*  **DO NOT** add solutions that are similar to any existing solutions. If you think it is **_similar but better_**, then try to merge (or replace) the existing similar solution.
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* Add an explanation of your solution.
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* Categorize the solution in one of the following categories — **Basic**, **Intermediate** and **Advanced**. 
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* Please add your username only if you have added any **relevant main contents**. ( **_DO NOT_** _remove any existing usernames_)
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> See  <a href='http://forum.freecodecamp.com/t/algorithm-article-template/14272' target='_blank' rel='nofollow'>**`Wiki Challenge Solution Template`**</a> for reference.
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