fix(curriculum): Rewrote the Write Higher-Order Arrow Functions challenge and moved to Functional Programming section (#35954)

* fix: reworded and moved challenge

* fix: removed extra line

Co-Authored-By: RandellDawson <5313213+RandellDawson@users.noreply.github.com>

* fix; removed extra line

Co-Authored-By: RandellDawson <5313213+RandellDawson@users.noreply.github.com>

* fix: reworded sentence

Co-Authored-By: RandellDawson <5313213+RandellDawson@users.noreply.github.com>

curriculum/challenges/_meta/es6/meta.json

@@ -36,10 +36,6 @@
       "587d7b88367417b2b2512b44",
       "Write Arrow Functions with Parameters"
     ],
-    [
-      "587d7b88367417b2b2512b45",
-      "Write Higher Order Arrow Functions"
-    ],
     [
       "587d7b88367417b2b2512b46",
       "Set Default Parameters for Your Functions"

curriculum/challenges/_meta/functional-programming/meta.json

@@ -68,6 +68,10 @@
       "587d7da9367417b2b2512b68",
       "Use the reduce Method to Analyze Data"
     ],
+    [
+      "587d7b88367417b2b2512b45",
+      "Use Higher-Order Functions map, filter, or reduce to Solve a Complex Problem"
+    ],
     [
       "587d7da9367417b2b2512b69",
       "Sort an Array Alphabetically using the sort Method"

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/es6/write-higher-order-arrow-functions.english.md

@@ -1,124 +0,0 @@
----
-id: 587d7b88367417b2b2512b45
-title: Write Higher-Order Arrow Functions
-challengeType: 1
----
-
-## Description
-<section id='description'>
-It's time to look at higher-order functions and their common pair, arrow functions.
-Arrow functions work really well when combined with higher-order functions, such as <code>map()</code>, <code>filter()</code>, and <code>reduce()</code>. <br>
-But what are these functions? Lets look at the simplest example <code>forEach()</code>, and run it on the following array of sample Facebook posts.
-<blockquote>let FBPosts = [<br>
-    {thumbnail: "someIcon", likes:432, shares: 600},<br>
-    {thumbnail: "Another icon", likes:300, shares: 501},<br>
-    {thumbnail: "Yet another", likes:40, shares: 550},<br>
-    {thumbnail: null, likes: 101, shares:0},<br>
-]</br>
-</blockquote>
-Of the two <code>forEach()</code> versions below, both perform the exact same log function, and each takes an anonymous callback with a parameter <code>post</code>. The difference is the syntax. One uses an arrow function and the other does not.  
-<blockquote>
-<strong>ES5</strong><br>
-FBpost.forEach(function(post) {<br>
-    console.log(post) // log each post here<br>
-    });<br>
-<strong>ES6</strong><br>
-FBpost.forEach((post) => {<br>
-    console.log(post) // log each post here<br>
-    });<br>
-
-</blockquote>
-<code>filter()</code> is very similar. Below it will iterate over the <code>FBPosts</code> array, perform the logic to filter out the items that do not meet the requirements, and return a new array, <code>results</code>.
-
-<blockquote>
-let results = arr1.filter((post) => {
-	return post.thumbnail !== null && post.likes > 100 && post.shares > 500
-});<br><br>
-console.log(results); // [{thumbnail: "someIcon", likes: 432, shares: 600}, {thumbnail: "Another icon", likes: 300, shares: 501}]
-</blockquote>
-
-</section>
-
-
-
-## Instructions
-<section id='instructions'>
-Use arrow function syntax to compute the square of <em>only</em> the positive integers (decimal numbers are not integers) in the array <code>realNumberArray</code> and store the new array in the variable <code>squaredIntegers</code>.
-</section>
-
-## Tests
-<section id='tests'>
-
-```yml
-tests:
-  - text: <code>squareList</code> should be a <code>function</code>.
-    testString: assert.typeOf(squareList, 'function'), '<code>squareList</code> should be a <code>function</code>';
-  - text: <code>squareList</code> should be a constant variable (by using  <code>const</code>).
-    testString: getUserInput => assert(getUserInput('index').match(/const\s+squaredIntegers/g), '<code>squaredIntegers</code> should be a constant variable (by using <code>const</code>).');
-  - text: <code>function</code> keyword was not used.
-    testString: getUserInput => assert(!getUserInput('index').match(/function/g), '<code>function</code> keyword was not used.');
-  - text: loop should not be used
-    testString: getUserInput => assert(!getUserInput('index').match(/(for)|(while)/g), 'loop should not be used');
-  - text: <code>map</code>, <code>filter</code>, or <code>reduce</code> should be used
-    testString: getUserInput => assert(getUserInput('index').match(/map|filter|reduce/g), '<code>map</code>, <code>filter</code>, or <code>reduce</code> should be used');
-  - text: The function should return an <code>array</code> called <code>squaredIntegers</code>
-    testString: assert(Array.isArray(squaredIntegers), '<code>squaredIntegers</code> should be an <code>array</code>');
-  - text: <code>squaredIntegers</code> should be <code>[16, 1764, 36]</code>
-    testString: assert.deepStrictEqual(squaredIntegers, [16, 1764, 36], '<code>squaredIntegers</code> should be <code>[16, 1764, 36]</code>');
-
-```
-
-</section>
-
-## Challenge Seed
-<section id='challengeSeed'>
-
-<div id='js-seed'>
-
-```js
-const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34, -2];
-const squareList = (arr) => {
-  "use strict";
-  const positiveIntegers = arr.filter((num) => {
-     // add code here
-  });
-  const squaredIntegers = positiveIntegers.map((num) => {
-       // add code here
-  });
-
-  return squaredIntegers;
-};
-// test your code
-const squaredIntegers = squareList(realNumberArray);
-console.log(squaredIntegers);
-
-```
-
-</div>
-
-
-
-</section>
-
-## Solution
-<section id='solution'>
-
-```js
-const realNumberArray = [4, 5.6, -9.8, 3.14, 42, 6, 8.34, -2];
-const squareList = (arr) => {
-  "use strict";
-  const positiveIntegers = arr.filter((num) => {
-    return num >= 0 && Number.isInteger(num);
-      // add code here
-  });
-  const squaredIntegers = positiveIntegers.map((num) => {
-    // add code here
-    return num ** 2;
-  });
-  // add code here
-  return squaredIntegers;
-};
-// test your code
-const squaredIntegers = squareList(realNumberArray);
-```
-</section>

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/functional-programming/use-higher-order-functions-map-filter-or-reduce-to-solve-a-complex-problem.english.md

@@ -0,0 +1,82 @@
+---
+id: 587d7b88367417b2b2512b45
+title: Use Higher-Order Functions map, filter, or reduce to Solve a Complex Problem 
+challengeType: 1
+---
+
+## Description
+<section id='description'>
+Now that you have worked through a few challenges using higher-order functions like <code>map()</code>, <code>filter()</code>, and <code>reduce()</code>, you now get to apply them to solve a more complex challenge.
+</section>
+
+## Instructions
+<section id='instructions'>
+We have defined a function named <code>squareList</code>.  You need to complete the code for the <code>squareList</code> function using any combination of <code>map()</code>, <code>filter()</code>, and <code>reduce()</code> so that it returns a new array containing only the square of <em>only</em> the positive integers (decimal numbers are not integers) when an array of real numbers is passed to it.  An example of an array containing only real numbers is <code>[-3, 4.8, 5, 3, -3.2]</code>.
+<strong>Note:</strong> Your function should not use any kind of <code>for</code> or <code>while</code> loops or the <code>forEach()</code> function.
+</section>
+
+## Tests
+<section id='tests'>
+
+```yml
+tests:
+  - text: <code>squareList</code> should be a <code>function</code>.
+    testString: assert.typeOf(squareList, 'function'), '<code>squareList</code> should be a <code>function</code>';
+  - text: for or while loops or forEach should not be used.
+    testString: assert(!removeJSComments(code).match(/for|while|forEach/g));
+  - text: <code>map</code>, <code>filter</code>, or <code>reduce</code> should be used.
+    testString: assert(removeJSComments(code).match(/\.(map|filter|reduce)\s*\(/g));
+  - text: The function should return an <code>array</code>.
+    testString: assert(Array.isArray(squareList([4, 5.6, -9.8, 3.14, 42, 6, 8.34, -2])));
+  - text: <code>squareList([4, 5.6, -9.8, 3.14, 42, 6, 8.34, -2])</code> should return <code>[16, 1764, 36]</code>.
+    testString: assert.deepStrictEqual(squareList([4, 5.6, -9.8, 3.14, 42, 6, 8.34, -2]), [16, 1764, 36]);
+  - text: <code>squareList([-3.7, -5, 3, 10, 12.5, 7, -4.5, -17, 0.3])</code> should return <code>[9, 100, 49]</code>.
+    testString: assert.deepStrictEqual(squareList([-3.7, -5, 3, 10, 12.5, 7, -4.5, -17, 0.3]), [9, 100, 49]);  
+```
+
+</section>
+
+## Challenge Seed
+<section id='challengeSeed'>
+
+<div id='js-seed'>
+
+```js
+const squareList = (arr) => {
+  // only change code below this line
+  return arr;
+  // only change code above this line
+};
+
+// test your code
+const squaredIntegers = squareList([-3, 4.8, 5, 3, -3.2]);
+console.log(squaredIntegers);
+```
+
+</div>
+
+<div id='js-teardown'>
+
+```js
+const removeJSComments = str => str.replace(/\/\*[\s\S]*?\*\/|\/\/.*$/gm, '');
+```
+
+</div>
+
+</section>
+
+## Solution
+<section id='solution'>
+
+```js
+const squareList = (arr) => {
+  const positiveIntegers = arr.filter(num => {
+    return num >= 0 && Number.isInteger(num);
+  });
+  const squaredIntegers = positiveIntegers.map(num => {
+    return num ** 2;
+  });
+  return squaredIntegers;
+};
+```
+</section>

guide/english/certifications/javascript-algorithms-and-data-structures/functional-programming/use-higher-order-functions-map-filter-or-reduce-to-solve-a-complex-problem/index.md

@@ -1,5 +1,5 @@
 ---
-title: Write Higher Order Arrow Functions
+title: Use Higher-Order Functions map, filter, or reduce to Solve a Complex Problem 
 ---
 ![:triangular_flag_on_post:](https://forum.freecodecamp.com/images/emoji/emoji_one/triangular_flag_on_post.png?v=3 ":triangular_flag_on_post:") Remember to use <a>**`Read-Search-Ask`**</a> if you get stuck. Try to pair program ![:busts_in_silhouette:](https://forum.freecodecamp.com/images/emoji/emoji_one/busts_in_silhouette.png?v=3 ":busts_in_silhouette:") and write your own code ![:pencil:](https://forum.freecodecamp.com/images/emoji/emoji_one/pencil.png?v=3 ":pencil:")
 
@@ -32,35 +32,26 @@ We need to compute and square values from the `realNumberArray` and store them i
 **Solution ahead!**
 
 ## ![:beginner:](https://forum.freecodecamp.com/images/emoji/emoji_one/beginner.png?v=3 ":beginner:") Code solution:
-```javascript
+```js
-    const squareList = (arr) => {
+const squareList = (arr) => arr
-      "use strict";
+  .filter((num) => num > 0 && num % parseInt(num) === 0)
-      const squaredIntegers = arr.filter((num) => num > 0 && num % parseInt(num) === 0).map((num) => Math.pow(num, 2));
+  .map((num) => Math.pow(num, 2));
-      return squaredIntegers;
-    };
-
-    // test your code
-    const squaredIntegers = squareList(realNumberArray);
-    console.log(squaredIntegers);
 ```
-- [Run code at codepen.io](https://codepen.io/dylantyates/pen/WyWoYJ)
+
 ### Code explanation:
 
 Uses the operator `filter()` and `map()` functions to square all positive integers in a given array.
 
-
 ## Alternative code solution:
-```javascript
+```js
-
+const squareList = (arr) => {
-  // change code below this line
+  return arr.reduce((sqrIntegers, num) => {
-  const squaredIntegers = arr.filter((param) => Number.isInteger(param) && param >= 0).map(x => x * x);
+    return Number.isInteger(num) && num > 0
-  // change code above this line
+      ? sqrIntegers.concat(num * num)
-
+      : sqrIntegers;
+  }, []);
+};
 ```
-- [Run code at repl.it](https://repl.it/@AdrianSkar/ES6-Write-higher-order-arrow-functions)
-### Code explanation
-This does basically the same but uses the `isInteger()` method to check the numbers.
-
 
 ### Resources