diff --git a/hackerrank/10 Days of JavaScript/0 - Data Types.js b/hackerrank/10 Days of JavaScript/0 - Data Types.js
new file mode 100644
index 0000000..641bc7c
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/0 - Data Types.js
@@ -0,0 +1,50 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/* All three parameters to this function are strings. */
+function performOperation(secondInteger, secondDecimal, secondString) {
+ const firstInteger = 4;
+ const firstDecimal = 4.0;
+ const firstString = 'HackerRank ';
+
+ console.log(firstInteger + parseInt(secondInteger));
+ console.log(firstDecimal + parseFloat(secondDecimal));
+ console.log(firstString + secondString);
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const secondInteger = readLine();
+ const secondDecimal = readLine();
+ const secondString = readLine();
+
+ performOperation(secondInteger, secondDecimal, secondString);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/0 - Hello World.js b/hackerrank/10 Days of JavaScript/0 - Hello World.js
new file mode 100644
index 0000000..6e75b60
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/0 - Hello World.js
@@ -0,0 +1,42 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function greeting(message) {
+ console.log('Hello, World!');
+ console.log(message);
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const parameterVariable = readLine();
+
+ greeting(parameterVariable);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/1 - Arthmetic.js b/hackerrank/10 Days of JavaScript/1 - Arthmetic.js
new file mode 100644
index 0000000..47dad8b
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/1 - Arthmetic.js
@@ -0,0 +1,47 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function getArea(length, width) {
+ return length * width;
+}
+
+function getPerimeter(length, width) {
+ return 2 * (length + width);
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const length = +(readLine());
+ const width = +(readLine());
+
+ console.log(getArea(length, width));
+ console.log(getPerimeter(length, width));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/1 - Fnxn.js b/hackerrank/10 Days of JavaScript/1 - Fnxn.js
new file mode 100644
index 0000000..a920aac
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/1 - Fnxn.js
@@ -0,0 +1,47 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function factorial(n) {
+ if (n < 0) {
+ throw "Input to 'factorial()' must be non-negative";
+ } else if (n == 0 || n == 1) {
+ return 1;
+ } else {
+ return n * factorial(n - 1);
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const n = +(readLine());
+
+ console.log(factorial(n));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/1 - Let.js b/hackerrank/10 Days of JavaScript/1 - Let.js
new file mode 100644
index 0000000..923ed86
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/1 - Let.js
@@ -0,0 +1,48 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function main() {
+ const PI = Math.PI;
+ const r = parseFloat(readLine());
+
+ console.log(PI * (r ** 2));
+ console.log(2 * PI * r);
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+ try {
+ // Attempt to redefine the value of constant variable PI
+ PI = 0;
+ // Attempt to print the value of PI
+ console.log(PI);
+ } catch(error) {
+ console.error("You correctly declared 'PI' as a constant.");
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/2 - If.js b/hackerrank/10 Days of JavaScript/2 - If.js
new file mode 100644
index 0000000..51ff179
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/2 - If.js
@@ -0,0 +1,61 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function getGrade(score) {
+ let grade;
+
+ if (score > 30) {
+ throw "score must be <= 30";
+ } else if (score > 25) {
+ grade = 'A';
+ } else if (score > 20) {
+ grade = 'B';
+ } else if (score > 15) {
+ grade = 'C';
+ } else if (score > 10) {
+ grade = 'D';
+ } else if (score > 5) {
+ grade = 'E';
+ } else if (score >= 0) {
+ grade = 'F';
+ } else {
+ throw "score must be non-negative";
+ }
+
+ return grade;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const score = +(readLine());
+
+ console.log(getGrade(score));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
\ No newline at end of file
diff --git a/hackerrank/10 Days of JavaScript/2 - Loop.js b/hackerrank/10 Days of JavaScript/2 - Loop.js
new file mode 100644
index 0000000..9b1b6ec
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/2 - Loop.js
@@ -0,0 +1,58 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function isVowel(ch) {
+ ch = ch.toLowerCase();
+ return ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u';
+}
+
+function vowelsAndConsonants(s) {
+ let vowels = [];
+ let consonants = [];
+
+ for (let ch of s) {
+ if (isVowel(ch)) {
+ vowels.push(ch);
+ } else {
+ consonants.push(ch);
+ }
+ }
+
+ console.log(vowels.join('\n'));
+ console.log(consonants.join('\n'));
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const s = readLine();
+
+ vowelsAndConsonants(s);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/2 - Switch.js b/hackerrank/10 Days of JavaScript/2 - Switch.js
new file mode 100644
index 0000000..8ff6a2f
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/2 - Switch.js
@@ -0,0 +1,65 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function getLetter(s) {
+ const aSet = new Set(['a', 'e', 'i', 'o', 'u']);
+ const bSet = new Set(['b', 'c', 'd', 'f', 'g']);
+ const cSet = new Set(['h', 'j', 'k', 'l', 'm']);
+ const dSet = new Set(['n', 'p', 'q', 'r', 's',
+ 't', 'v', 'w', 'x', 'y', 'z']);
+
+ let letter;
+ const firstChar = s.charAt(0);
+ switch (true) {
+ case aSet.has(firstChar):
+ letter = 'A';
+ break;
+ case bSet.has(firstChar):
+ letter = 'B';
+ break;
+ case cSet.has(firstChar):
+ letter = 'C';
+ break;
+ case dSet.has(firstChar):
+ letter = 'D';
+ break;
+ default:
+ throw "Unexpected first character"
+ }
+ return letter;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const s = readLine();
+
+ console.log(getLetter(s));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/3 - Array.js b/hackerrank/10 Days of JavaScript/3 - Array.js
new file mode 100644
index 0000000..ced81e3
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/3 - Array.js
@@ -0,0 +1,62 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/**
+ * Finds the second largest value in the array, in one pass.
+ * If the array only has one distinct element, returns that element.
+ */
+function getSecondLargest(nums) {
+ let largest = Number.MIN_VALUE;
+ let secondLargest = Number.MIN_VALUE;
+
+ for (let num of nums) {
+ if (num > largest) {
+ secondLargest = largest
+ largest = num;
+ } else if (num > secondLargest && num < largest) {
+ secondLargest = num;
+ }
+ }
+
+ if (secondLargest == Number.MIN_VALUE) {
+ return largest; // only one distinct element
+ } else {
+ return secondLargest;
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const n = +(readLine());
+ const nums = readLine().split(' ').map(Number);
+
+ console.log(getSecondLargest(nums));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/3 - Throw.js b/hackerrank/10 Days of JavaScript/3 - Throw.js
new file mode 100644
index 0000000..ed73a48
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/3 - Throw.js
@@ -0,0 +1,55 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function isPositive(a) {
+ if (a > 0) {
+ return "YES";
+ } else if (a == 0) {
+ throw new Error("Zero Error");
+ } else {
+ throw new Error("Negative Error");
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const n = +(readLine());
+
+ for (let i = 0; i < n; i++) {
+ const a = +(readLine());
+
+ try {
+ console.log(isPositive(a));
+ } catch (e) {
+ console.log(e.message);
+ }
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/3 - Try.js b/hackerrank/10 Days of JavaScript/3 - Try.js
new file mode 100644
index 0000000..ece348b
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/3 - Try.js
@@ -0,0 +1,49 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function reverseString(s) {
+ try {
+ let array = s.split("");
+ array.reverse();
+ s = array.join("");
+ } catch (e) {
+ console.log(e.message);
+ } finally {
+ console.log(s);
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const s = eval(readLine());
+
+ reverseString(s);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/4 - Class.js b/hackerrank/10 Days of JavaScript/4 - Class.js
new file mode 100644
index 0000000..7b5e326
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/4 - Class.js
@@ -0,0 +1,21 @@
+class Polygon {
+ constructor(sideLengths) {
+ this.sideLengths = sideLengths;
+ }
+
+ perimeter() {
+ return this.sideLengths.reduce((a, b) => a + b);
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+const rectangle = new Polygon([10, 20, 10, 20]);
+const square = new Polygon([10, 10, 10, 10]);
+const pentagon = new Polygon([10, 20, 30, 40, 43]);
+
+console.log(rectangle.perimeter());
+console.log(square.perimeter());
+console.log(pentagon.perimeter());
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/4 - Count.js b/hackerrank/10 Days of JavaScript/4 - Count.js
new file mode 100644
index 0000000..faf6dc6
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/4 - Count.js
@@ -0,0 +1,57 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/**
+ * Returns a count of the total number of objects 'o' satisfying o.x == o.y.
+ */
+function getCount(objects) {
+ let count = 0;
+ for (let o of objects) {
+ if (o.x == o.y) {
+ count++;
+ }
+ }
+ return count;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const n = +(readLine());
+ let objects = [];
+
+ for (let i = 0; i < n; i++) {
+ const [a, b] = readLine().split(' ');
+
+ objects.push({x: +(a), y: +(b)});
+ }
+
+ console.log(getCount(objects));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
\ No newline at end of file
diff --git a/hackerrank/10 Days of JavaScript/4 - Rect.js b/hackerrank/10 Days of JavaScript/4 - Rect.js
new file mode 100644
index 0000000..4f79e6c
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/4 - Rect.js
@@ -0,0 +1,50 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function Rectangle(a, b) {
+ this.length = a;
+ this.width = b;
+ this.perimeter = 2 * (a + b);
+ this.area = a * b;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const a = +(readLine());
+ const b = +(readLine());
+
+ const rec = new Rectangle(a, b);
+
+ console.log(rec.length);
+ console.log(rec.width);
+ console.log(rec.perimeter);
+ console.log(rec.area);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/5 - Arrow.js b/hackerrank/10 Days of JavaScript/5 - Arrow.js
new file mode 100644
index 0000000..db95d10
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/5 - Arrow.js
@@ -0,0 +1,45 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/**
+ * Doubles all even numbers in the array, and triples all odd numbers.
+ */
+function modifyArray(nums) {
+ return nums.map(n => (n % 2 == 0) ? (n * 2) : (n * 3));
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const n = +(readLine());
+ const a = readLine().split(' ').map(Number);
+
+ console.log(modifyArray(a).toString().split(',').join(' '));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/5 - Inheritance.js b/hackerrank/10 Days of JavaScript/5 - Inheritance.js
new file mode 100644
index 0000000..36756d5
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/5 - Inheritance.js
@@ -0,0 +1,35 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+class Rectangle {
+ constructor(w, h) {
+ this.w = w;
+ this.h = h;
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+Rectangle.prototype.area = function () {
+ return this.w * this.h;
+}
+
+class Square extends Rectangle {
+ constructor(sideLength) {
+ super(sideLength, sideLength);
+ }
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+if (JSON.stringify(Object.getOwnPropertyNames(Square.prototype)) === JSON.stringify([ 'constructor' ])) {
+ const rec = new Rectangle(3, 4);
+ const sqr = new Square(3);
+
+ console.log(rec.area());
+ console.log(sqr.area());
+} else {
+ console.log(-1);
+ console.log(-1);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/5 - Literals.js b/hackerrank/10 Days of JavaScript/5 - Literals.js
new file mode 100644
index 0000000..51457a8
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/5 - Literals.js
@@ -0,0 +1,60 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/*
+ * Determine the original side lengths and return an array:
+ * - The first element is the length of the shorter side
+ * - The second element is the length of the longer side
+ *
+ * Parameters:
+ * strings: The tagged template literal's array of strings.
+ * values: An array of: [area, perimeter].
+ */
+function sides(strings, ...values) {
+ const A = values[0];
+ const P = values[1];
+ const s1 = (P + (P ** 2 - (16 * A)) ** 0.5) / 4;
+ const s2 = A / s1;
+ return [s1, s2].sort();
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ let s1 = +(readLine());
+ let s2 = +(readLine());
+
+ [s1, s2] = [s1, s2].sort();
+
+ const [x, y] = sides`The area is: ${s1 * s2}.\nThe perimeter is: ${2 * (s1 + s2)}.`;
+
+ console.log((s1 === x) ? s1 : -1);
+ console.log((s2 === y) ? s2 : -1);
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/6 - Bitwise.js b/hackerrank/10 Days of JavaScript/6 - Bitwise.js
new file mode 100644
index 0000000..3e121bd
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/6 - Bitwise.js
@@ -0,0 +1,48 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+/**
+ * See the Discussion tab on HackerRank for some explanations of this solution.
+ */
+function getMaxLessThanK(n, k) {
+ return (((k - 1) | k) <= n) ? (k - 1) : (k - 2);
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const q = +(readLine());
+
+ for (let i = 0; i < q; i++) {
+ const [n, k] = readLine().split(' ').map(Number);
+
+ console.log(getMaxLessThanK(n, k));
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/6 - Dates.js b/hackerrank/10 Days of JavaScript/6 - Dates.js
new file mode 100644
index 0000000..90800c3
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/6 - Dates.js
@@ -0,0 +1,49 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function getDayName(dateString) {
+ const days = ["Sunday", "Monday", "Tuesday", "Wednesday",
+ "Thursday", "Friday", "Saturday"];
+ const date = new Date(dateString);
+ const dayNum = date.getDay();
+ return days[dayNum];
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const d = +(readLine());
+
+ for (let i = 0; i < d; i++) {
+ const date = readLine();
+
+ console.log(getDayName(date));
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/7 - Re1.js b/hackerrank/10 Days of JavaScript/7 - Re1.js
new file mode 100644
index 0000000..8768236
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/7 - Re1.js
@@ -0,0 +1,43 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function regexVar() {
+ /* Matches a string that starts and ends with the same vowel. */
+ return /^([aeiou]).*\1$/;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const re = regexVar();
+ const s = readLine();
+
+ console.log(re.test(s));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/7 - Re2.js b/hackerrank/10 Days of JavaScript/7 - Re2.js
new file mode 100644
index 0000000..4866b3d
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/7 - Re2.js
@@ -0,0 +1,44 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function regexVar() {
+ /* Matches a string that starts with 'Mr.', 'Mrs.', 'Ms.', 'Dr.', or 'Er.',
+ * followed by one or more letters. */
+ return /^(?:Mr|Mrs|Ms|Dr|Er)\.[a-zA-Z]+$/;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const re = regexVar();
+ const s = readLine();
+
+ console.log(!!s.match(re));
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/7 - Re3.js b/hackerrank/10 Days of JavaScript/7 - Re3.js
new file mode 100644
index 0000000..8bf96c9
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/7 - Re3.js
@@ -0,0 +1,47 @@
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+'use strict';
+
+process.stdin.resume();
+process.stdin.setEncoding('utf-8');
+
+let inputString = '';
+let currentLine = 0;
+
+process.stdin.on('data', inputStdin => {
+ inputString += inputStdin;
+});
+
+process.stdin.on('end', _ => {
+ inputString = inputString.trim().split('\n').map(string => {
+ return string.trim();
+ });
+
+ main();
+});
+
+function readLine() {
+ return inputString[currentLine++];
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
+
+function regexVar() {
+ /* Matches ALL occurrences of numbers in a string. */
+ return /(\d)+/g;
+}
+
+/* ************************************************************************** */
+/* --------------------------- begin locked code ---------------------------- */
+function main() {
+ const re = regexVar();
+ const s = readLine();
+
+ const r = s.match(re);
+
+ for (const e of r) {
+ console.log(e);
+ }
+}
+/* ---------------------------- end locked code ----------------------------- */
+/* ************************************************************************** */
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/css/buttonsGrid.css b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/css/buttonsGrid.css
new file mode 100644
index 0000000..de289f3
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/css/buttonsGrid.css
@@ -0,0 +1,9 @@
+#btns {
+ width: 75%;
+}
+
+.btn {
+ width: 30%;
+ height: 48px;
+ font-size: 24px;
+}
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/index.html b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/index.html
new file mode 100644
index 0000000..41bc11f
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/index.html
@@ -0,0 +1,23 @@
+
+
+
+
+ Buttons Grid
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/js/buttonsGrid.js b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/js/buttonsGrid.js
new file mode 100644
index 0000000..0b85c19
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Buttons Container/js/buttonsGrid.js
@@ -0,0 +1,12 @@
+/* Could adapt this to a general matrix rotation function */
+btn5.onclick = function() {
+ let temp = btn1.innerHTML;
+ btn1.innerHTML = btn4.innerHTML;
+ btn4.innerHTML = btn7.innerHTML;
+ btn7.innerHTML = btn8.innerHTML;
+ btn8.innerHTML = btn9.innerHTML;
+ btn9.innerHTML = btn6.innerHTML;
+ btn6.innerHTML = btn3.innerHTML;
+ btn3.innerHTML = btn2.innerHTML;
+ btn2.innerHTML = temp;
+}
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/css/button.css b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/css/button.css
new file mode 100644
index 0000000..cd35f6c
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/css/button.css
@@ -0,0 +1,5 @@
+#btn {
+ width: 96px;
+ height: 48px;
+ font-size: 24px;
+}
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/index.html b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/index.html
new file mode 100644
index 0000000..98bde57
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/index.html
@@ -0,0 +1,13 @@
+
+
+
+
+
+ Button
+
+
+
+
+
+
+
diff --git a/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/js/button.js b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/js/button.js
new file mode 100644
index 0000000..e5f4029
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 8 - Create a Button/js/button.js
@@ -0,0 +1,9 @@
+var btn = document.createElement("Button");
+
+btn.innerHTML = "0";
+btn.id = "btn";
+document.body.appendChild(btn);
+
+btn.onclick = function() {
+ btn.innerHTML++;
+}
diff --git a/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/css/binaryCalculator.css b/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/css/binaryCalculator.css
new file mode 100644
index 0000000..2a480ae
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/css/binaryCalculator.css
@@ -0,0 +1,33 @@
+body {
+ width: 33%;
+}
+
+#res {
+ background-color: lightgray;
+ border: solid;
+ height: 48px;
+ font-size: 20px;
+}
+
+#btns button {
+ width: 25%;
+ height: 36px;
+ font-size: 18px;
+ margin:0;
+ float: left;
+}
+
+#btn0, #btn1 {
+ background-color: lightgreen;
+ color: brown;
+}
+
+#btnClr, #btnEql {
+ background-color: darkgreen;
+ color: white;
+}
+
+#btnSum, #btnSub, #btnMul, #btnDiv {
+ background-color: black;
+ color: red;
+}
diff --git a/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/index.html b/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/index.html
new file mode 100644
index 0000000..9ee2b8a
--- /dev/null
+++ b/hackerrank/10 Days of JavaScript/Day 9 - Binary Calculator/index.html
@@ -0,0 +1,25 @@
+
+
+
+
+ Binary Calculator
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+