Add "Ones and Zeros" kata

Author: juan-antonio-ledesma

7-kyu/ones-and-zeros.md

@@ -0,0 +1,38 @@
+<h1>Ones and Zeros <sup><sup>7 Kyu</sup></sup></h1>
+
+<sup>
+  <a href="https://www.codewars.com/kata/578553c3a1b8d5c40300037c">
+    <strong>LINK TO THE KATA</strong>
+  </a> - <code>FUNDAMENTALS</code> <code>ARRAYS</code>
+</sup>
+
+## Description
+
+Given an array of ones and zeroes, convert the equivalent binary value to an integer.
+
+Eg: `[0, 0, 0, 1]` is treated as `0001` which is the binary representation of `1`.
+
+Examples:
+
+```
+Testing: [0, 0, 0, 1] ==> 1
+Testing: [0, 0, 1, 0] ==> 2
+Testing: [0, 1, 0, 1] ==> 5
+Testing: [1, 0, 0, 1] ==> 9
+Testing: [0, 0, 1, 0] ==> 2
+Testing: [0, 1, 1, 0] ==> 6
+Testing: [1, 1, 1, 1] ==> 15
+Testing: [1, 0, 1, 1] ==> 11
+```
+
+However, the arrays can have varying lengths, not just limited to `4`.
+
+## Solutions
+
+```javascript
+const binaryArrayToNumber = arr => arr.reduce((acc, cur) => acc * 2 + cur, 0)
+```
+
+```javascript
+const binaryArrayToNumber = arr => parseInt(arr.join(''), 2)
+```

README.md

@@ -165,6 +165,7 @@ JavaScript katas on Codewars are programming challenges that help you improve yo
 - **[Merge two arrays](./7-kyu/merge-two-arrays.md)**<br><sup>`FUNDAMENTALS` `ARRAYS`</sup>
 - **[Mumbling](./7-kyu/mumbling.md)**<br><sup>`FUNDAMENTALS` `STRINGS` `PUZZLES`</sup>
 - **[Odd or Even?](./7-kyu/odd-or-even.md)**<br><sup>`FUNDAMENTALS` `ARRAYS`</sup>
+- **[Ones and Zeros](./7-kyu/ones-and-zeros.md)**<br><sup>`FUNDAMENTALS` `ARRAYS`</sup>
 - **[Return the closest number multiple of 10](./7-kyu/return-the-closest-number-multiple-of-10.md)**<br><sup>`MATHEMATICS` `FUNDAMENTALS`</sup>
 - **[Sort array by string length](./7-kyu/sort-array-by-string-length.md)**<br><sup>`SORTING` `ARRAYS` `FUNDAMENTALS`</sup>
 - **[Sort Numbers](./7-kyu/sort-numbers.md)**<br><sup>`FUNDAMENTALS`</sup>