Add solutions to calculator, palindrome and caesar exercises

Author: Nevrmnd

caesar/caesar.js

@@ -1,5 +1,23 @@
-const caesar = function() {
+const caesar = function (word, num) {
+	const arr = [];
+	for (let i = 0; i < word.length; i++) {
+		arr.push(word.charCodeAt(i));
+	}
+	const shifted = arr.map((x) => {
+		if (x >= 97 && x <= 122) {
+			//if num is positive; (26 + num % 26) will be equal to num
+			// if num is negative; (26 + num % 26) will be the same as subtracting num from 26
+			const shift = (x - 97 + (26 + (num % 26))) % 26;
+			return String.fromCharCode(shift + 97);
+		} else if (x >= 65 && x <= 90) {
+			const shift = (x - 65 + (26 + (num % 26))) % 26;
+			return String.fromCharCode(shift + 65);
+		} else {
+			return String.fromCharCode(x);
+		}
+	});
 
-}
+	return shifted.join("");
+};
 
-module.exports = caesar
+module.exports = caesar;

caesar/caesar.spec.js

@@ -1,25 +1,25 @@
-const caesar = require('./caesar')
+const caesar = require("./caesar");
 
-describe('caesar', function() {
-  it('works with single letters', function() {
-    expect(caesar('A', 1)).toEqual('B');
-  });
-  xit('works with words', function() {
-    expect(caesar('Aaa', 1)).toEqual('Bbb');
-  });
-  xit('works with phrases', function() {
-    expect(caesar('Hello, World!', 5)).toEqual('Mjqqt, Btwqi!');
-  });
-  xit('works with negative shift', function() {
-    expect(caesar('Mjqqt, Btwqi!', -5)).toEqual('Hello, World!');
-  });
-  xit('wraps', function() {
-    expect(caesar('Z', 1)).toEqual('A');
-  });
-  xit('works with large shift factors', function() {
-    expect(caesar('Hello, World!', 75)).toEqual('Ebiil, Tloia!');
-  });
-  xit('works with large negative shift factors', function() {
-    expect(caesar('Hello, World!', -29)).toEqual('Ebiil, Tloia!');
-  });
+describe("caesar", function () {
+	it("works with single letters", function () {
+		expect(caesar("A", 1)).toEqual("B");
+	});
+	it("works with words", function () {
+		expect(caesar("Aaa", 1)).toEqual("Bbb");
+	});
+	it("works with phrases", function () {
+		expect(caesar("Hello, World!", 5)).toEqual("Mjqqt, Btwqi!");
+	});
+	it("works with negative shift", function () {
+		expect(caesar("Mjqqt, Btwqi!", -5)).toEqual("Hello, World!");
+	});
+	it("wraps", function () {
+		expect(caesar("Z", 1)).toEqual("A");
+	});
+	it("works with large shift factors", function () {
+		expect(caesar("Hello, World!", 75)).toEqual("Ebiil, Tloia!");
+	});
+	it("works with large negative shift factors", function () {
+		expect(caesar("Hello, World!", -29)).toEqual("Ebiil, Tloia!");
+	});
 });

calculator/calculator.js

@@ -1,32 +1,44 @@
-function add () {
-	
+function add(a, b) {
+	return a + b;
 }
 
-function subtract () {
-	
+function subtract(a, b) {
+	return a - b;
 }
 
-function sum () {
-	
+function sum(arr) {
+	return arr.length === 0 ? 0 : arr.reduce((acc, val) => (acc += val));
 }
 
-function multiply () {
-	
+function multiply(arr) {
+	return arr.reduce((acc, val) => (acc *= val));
 }
 
-function power() {
-	
+function power(a, b) {
+	let expo = 1;
+	for (let i = 0; i < b; i++) {
+		expo *= a;
+	}
+	return expo;
 }
 
-function factorial() {
-	
+function factorial(n) {
+	let product = n;
+	if (n === 0) {
+		return 1;
+	} else {
+		for (let i = n - 1; i > 0; i--) {
+			product *= i;
+		}
+	}
+	return product;
 }
 
 module.exports = {
 	add,
 	subtract,
 	sum,
 	multiply,
-    power,
-	factorial
-}
+	power,
+	factorial,
+};

calculator/calculator.spec.js

@@ -1,77 +1,77 @@
-const calculator = require ('./calculator.js');
+const calculator = require("./calculator.js");
 
-describe('add', function() {
-	it('adds 0 and 0', function() {
-		expect(calculator.add(0,0)).toEqual(0);
+describe("add", function () {
+	it("adds 0 and 0", function () {
+		expect(calculator.add(0, 0)).toEqual(0);
 	});
 
-	xit('adds 2 and 2', function() {
-		expect(calculator.add(2,2)).toEqual(4);
+	it("adds 2 and 2", function () {
+		expect(calculator.add(2, 2)).toEqual(4);
 	});
 
-	xit('adds positive numbers', function() {
-		expect(calculator.add(2,6)).toEqual(8);
+	it("adds positive numbers", function () {
+		expect(calculator.add(2, 6)).toEqual(8);
 	});
 });
 
-describe('subtract', function() {
-	xit('subtracts numbers', function() {
-		expect(calculator.subtract(10,4)).toEqual(6);
+describe("subtract", function () {
+	it("subtracts numbers", function () {
+		expect(calculator.subtract(10, 4)).toEqual(6);
 	});
 });
 
-describe('sum', function() {
-	xit('computes the sum of an empty array', function() {
+describe("sum", function () {
+	it("computes the sum of an empty array", function () {
 		expect(calculator.sum([])).toEqual(0);
 	});
 
-	xit('computes the sum of an array of one number', function() {
+	it("computes the sum of an array of one number", function () {
 		expect(calculator.sum([7])).toEqual(7);
 	});
 
-	xit('computes the sum of an array of two numbers', function() {
-		expect(calculator.sum([7,11])).toEqual(18);
+	it("computes the sum of an array of two numbers", function () {
+		expect(calculator.sum([7, 11])).toEqual(18);
 	});
 
-	xit('computes the sum of an array of many numbers', function() {
-		expect(calculator.sum([1,3,5,7,9])).toEqual(25);
+	it("computes the sum of an array of many numbers", function () {
+		expect(calculator.sum([1, 3, 5, 7, 9])).toEqual(25);
 	});
 });
 
-describe('multiply', function() {
-	xit('multiplies two numbers', function() {
-		expect(calculator.multiply([2,4])).toEqual(8);
+describe("multiply", function () {
+	it("multiplies two numbers", function () {
+		expect(calculator.multiply([2, 4])).toEqual(8);
 	});
 
-	xit('multiplies several numbers', function() {
-		expect(calculator.multiply([2,4,6,8,10,12,14])).toEqual(645120);
+	it("multiplies several numbers", function () {
+		expect(calculator.multiply([2, 4, 6, 8, 10, 12, 14])).toEqual(645120);
 	});
 });
 
-describe('power', function() {
-	xit('raises one number to the power of another number', function() {
-		expect(calculator.power(4,3)).toEqual(64); // 4 to third power is 64
+describe("power", function () {
+	it("raises one number to the power of another number", function () {
+		expect(calculator.power(4, 3)).toEqual(64); // 4 to third power is 64
 	});
 });
 
-describe('factorial', function() {
-	xit('computes the factorial of 0', function() {
+describe("factorial", function () {
+	it("computes the factorial of 0", function () {
 		expect(calculator.factorial(0)).toEqual(1); // 0! = 1
 	});
 
-	xit('computes the factorial of 1', function() {
+	it("computes the factorial of 1", function () {
 		expect(calculator.factorial(1)).toEqual(1);
 	});
 
-	xit('computes the factorial of 2', function() {
+	it("computes the factorial of 2", function () {
 		expect(calculator.factorial(2)).toEqual(2);
 	});
 
-	xit('computes the factorial of 5', function() {
+	it("computes the factorial of 5", function () {
 		expect(calculator.factorial(5)).toEqual(120);
 	});
 
-	xit('computes the factorial of 10', function() {
+	it("computes the factorial of 10", function () {
 		expect(calculator.factorial(10)).toEqual(3628800);
 	});
 });

fibonacci/fibonacci.js

@@ -1,5 +1,3 @@
-const fibonacci = function() {
+const fibonacci = function (num) {};
 
-}
-
-module.exports = fibonacci
+module.exports = fibonacci;

palindromes/palindromes.js

@@ -1,5 +1,14 @@
-const palindromes = function() {
+const palindromes = function (word) {
+	const arr = [];
+	const lower = word.toLowerCase();
+	for (let i = 0; i < word.length; i++) {
+		if (lower.charCodeAt(i) >= 97 && lower.charCodeAt(i) <= 122) {
+			arr.push(lower[i]);
+		}
+	}
+	const newWord = arr.join("");
+	const reversed = arr.reverse().join("");
+	return newWord === reversed;
+};
 
-}
-
-module.exports = palindromes
+module.exports = palindromes;

palindromes/palindromes.spec.js

@@ -1,23 +1,22 @@
-const palindromes = require('./palindromes')
-
-describe('palindromes', function() {
-  it('works with single words', function() {
-    expect(palindromes('racecar')).toEqual(true);
-  });
-  xit('works with punctuation ', function() {
-    expect(palindromes('racecar!')).toEqual(true);
-  });
-  xit('works with upper-case letters ', function() {
-    expect(palindromes('Racecar!')).toEqual(true);
-  });
-  xit('works with multiple words', function() {
-    expect(palindromes('A car, a man, a maraca.')).toEqual(true);
-  });
-  xit('works with multiple words', function() {
-    expect(palindromes('Animal loots foliated detail of stool lamina.')).toEqual(true);
-  });
-  xit('doesn\'t just always return true', function() {
-    expect(palindromes('ZZZZ car, a man, a maraca.')).toEqual(false);
-  });
+const palindromes = require("./palindromes");
 
+describe("palindromes", function () {
+	it("works with single words", function () {
+		expect(palindromes("racecar")).toEqual(true);
+	});
+	it("works with punctuation ", function () {
+		expect(palindromes("racecar!")).toEqual(true);
+	});
+	it("works with upper-case letters ", function () {
+		expect(palindromes("Racecar!")).toEqual(true);
+	});
+	it("works with multiple words", function () {
+		expect(palindromes("A car, a man, a maraca.")).toEqual(true);
+	});
+	it("works with multiple words", function () {
+		expect(palindromes("Animal loots foliated detail of stool lamina.")).toEqual(true);
+	});
+	it("doesn't just always return true", function () {
+		expect(palindromes("ZZZZ car, a man, a maraca.")).toEqual(false);
+	});
 });