Solve chapter 5 problems

Author: chriswakeley

08_calculator/calculator.js

@@ -1,25 +1,29 @@
-const add = function() {
-	
+const add = function(a, b) {
+	return a+b;
 };
 
-const subtract = function() {
-	
+const subtract = function(a, b) {
+	return a-b;
 };
 
-const sum = function() {
-	
+const sum = function(a) {
+	return a.reduce(((accum, current) => accum + current), 0);
 };
 
-const multiply = function() {
-
+const multiply = function(a) {
+  return a.reduce(((accum, current) => accum * current), 1);
 };
 
-const power = function() {
-	
+const power = function(a, b) {
+	return Math.pow(a, b);
 };
 
-const factorial = function() {
-	
+const factorial = function(a) {
+	let total = 1;
+  for(let i = 1; i <= a; i++){
+    total = total * i;
+  }
+  return total;
 };
 
 // Do not edit below this line

08_calculator/calculator.spec.js

@@ -5,73 +5,73 @@ describe('add', () => {
 		expect(calculator.add(0,0)).toBe(0);
 	});
 
-	test.skip('adds 2 and 2', () => {
+	test('adds 2 and 2', () => {
 		expect(calculator.add(2,2)).toBe(4);
 	});
 
-	test.skip('adds positive numbers', () => {
+	test('adds positive numbers', () => {
 		expect(calculator.add(2,6)).toBe(8);
 	});
 });
 
 describe('subtract', () => {
-	test.skip('subtracts numbers', () => {
+	test('subtracts numbers', () => {
 		expect(calculator.subtract(10,4)).toBe(6);
 	});
 });
 
 describe('sum', () => {
-	test.skip('computes the sum of an empty array', () => {
+	test('computes the sum of an empty array', () => {
 		expect(calculator.sum([])).toBe(0);
 	});
 
-	test.skip('computes the sum of an array of one number', () => {
+	test('computes the sum of an array of one number', () => {
 		expect(calculator.sum([7])).toBe(7);
 	});
 
-	test.skip('computes the sum of an array of two numbers', () => {
+	test('computes the sum of an array of two numbers', () => {
 		expect(calculator.sum([7,11])).toBe(18);
 	});
 
-	test.skip('computes the sum of an array of many numbers', () => {
+	test('computes the sum of an array of many numbers', () => {
 		expect(calculator.sum([1,3,5,7,9])).toBe(25);
 	});
 });
 
 describe('multiply', () => {
-	test.skip('multiplies two numbers', () => {
+	test('multiplies two numbers', () => {
 		expect(calculator.multiply([2,4])).toBe(8);
 	});
 
-	test.skip('multiplies several numbers', () => {
+	test('multiplies several numbers', () => {
 		expect(calculator.multiply([2,4,6,8,10,12,14])).toBe(645120);
 	});
 });
 
 describe('power', () => {
-	test.skip('raises one number to the power of another number', () => {
+	test('raises one number to the power of another number', () => {
 		expect(calculator.power(4,3)).toBe(64); // 4 to third power is 64
 	});
 });
 
 describe('factorial', () => {
-	test.skip('computes the factorial of 0', () => {
+	test('computes the factorial of 0', () => {
 		expect(calculator.factorial(0)).toBe(1); // 0! = 1
 	});
 
-	test.skip('computes the factorial of 1', () => {
+	test('computes the factorial of 1', () => {
 		expect(calculator.factorial(1)).toBe(1);
 	});
 
-	test.skip('computes the factorial of 2', () => {
+	test('computes the factorial of 2', () => {
 		expect(calculator.factorial(2)).toBe(2);
 	});
 
-	test.skip('computes the factorial of 5', () => {
+	test('computes the factorial of 5', () => {
 		expect(calculator.factorial(5)).toBe(120);
 	});
 
-	test.skip('computes the factorial of 10', () => {
+	test('computes the factorial of 10', () => {
 		expect(calculator.factorial(10)).toBe(3628800);
 	});
 });

09_palindromes/palindromes.js

@@ -1,5 +1,5 @@
-const palindromes = function () {
-
+const palindromes = function (input) {
+    return input.toLowerCase().split(/\W+/).join("").split('').reverse().join("") === input.toLowerCase().split(/\W+/).join("");
 };
 
 // Do not edit below this line

09_palindromes/palindromes.spec.js

@@ -4,19 +4,19 @@ describe('palindromes', () => {
   test('works with single words', () => {
     expect(palindromes('racecar')).toBe(true);
   });
-  test.skip('works with punctuation ', () => {
+  test('works with punctuation ', () => {
     expect(palindromes('racecar!')).toBe(true);
   });
-  test.skip('works with upper-case letters ', () => {
+  test('works with upper-case letters ', () => {
     expect(palindromes('Racecar!')).toBe(true);
   });
-  test.skip('works with multiple words', () => {
+  test('works with multiple words', () => {
     expect(palindromes('A car, a man, a maraca.')).toBe(true);
   });
-  test.skip('works with multiple words', () => {
+  test('works with multiple words', () => {
     expect(palindromes('Animal loots foliated detail of stool lamina.')).toBe(true);
   });
-  test.skip('doesn\'t just always return true', () => {
+  test('doesn\'t just always return true', () => {
     expect(palindromes('ZZZZ car, a man, a maracaz.')).toBe(false);
   });
 });

10_fibonacci/fibonacci.js

@@ -1,5 +1,17 @@
-const fibonacci = function() {
-
+const fibonacci = function(fibN) {
+    if(fibN < 1){
+        return "OOPS";
+    }
+    if(fibN < 3){
+        return 1;
+    }
+    let fibA, fibB;
+    fibA = fibB = 1;
+    for(let i = 2;i < fibN; i++){
+        fibA = fibA + fibB;
+        fibB = fibA - fibB;
+    }
+    return fibA;
 };
 
 // Do not edit below this line

10_fibonacci/fibonacci.spec.js

@@ -4,28 +4,28 @@ describe('fibonacci', () => {
   test('4th fibonacci number is 3', () => {
     expect(fibonacci(4)).toBe(3);
   });
-  test.skip('6th fibonacci number is 8', () => {
+  test('6th fibonacci number is 8', () => {
     expect(fibonacci(6)).toBe(8);
   });
-  test.skip('10th fibonacci number is 55', () => {
+  test('10th fibonacci number is 55', () => {
     expect(fibonacci(10)).toBe(55);
   });
-  test.skip('15th fibonacci number is 610', () => {
+  test('15th fibonacci number is 610', () => {
     expect(fibonacci(15)).toBe(610);
   });
-  test.skip('25th fibonacci number is 75025', () => {
+  test('25th fibonacci number is 75025', () => {
     expect(fibonacci(25)).toBe(75025);
   });
-  test.skip('doesn\'t accept negatives', () => {
+  test('doesn\'t accept negatives', () => {
     expect(fibonacci(-25)).toBe("OOPS");
   });
-  test.skip('DOES accept strings', () => {
+  test('DOES accept strings', () => {
     expect(fibonacci("1")).toBe(1);
   });
-  test.skip('DOES accept strings', () => {
+  test('DOES accept strings', () => {
     expect(fibonacci("2")).toBe(1);
   });
-  test.skip('DOES accept strings', () => {
+  test('DOES accept strings', () => {
     expect(fibonacci("8")).toBe(21);
   });
 });

11_getTheTitles/getTheTitles.js

@@ -1,5 +1,5 @@
-const getTheTitles = function() {
-
+const getTheTitles = function(books) {
+    return books.map(book => book.title);
 };
 
 // Do not edit below this line

12_findTheOldest/findTheOldest.js

@@ -1,5 +1,23 @@
-const findTheOldest = function() {
-
+const findTheOldest = function(people) {
+    return people.reduce((oldest,  nextPerson) => {
+        let age, oldestAge;
+        if (!("yearOfDeath" in nextPerson)){
+            age = (new Date()).getFullYear() - nextPerson.yearOfBirth;
+        }
+        else{
+            age = nextPerson.yearOfDeath - nextPerson.yearOfBirth;
+        }
+        if (!("yearOfDeath" in oldest)){
+            oldestAge = (new Date()).getFullYear() - oldest.yearOfBirth;
+        }
+        else{
+            oldestAge = oldest.yearOfDeath - oldest.yearOfBirth;
+        }
+        if(age > oldestAge){
+            oldest = nextPerson;
+        }
+        return oldest;
+    })
 };
 
 // Do not edit below this line

12_findTheOldest/findTheOldest.spec.js

@@ -21,7 +21,7 @@ describe('findTheOldest', () => {
     ]
     expect(findTheOldest(people).name).toBe('Ray');
   });
-  test.skip('finds the oldest person if someone is still living', () => {
+  test('finds the oldest person if someone is still living', () => {
     const people = [
       {
         name: "Carly",
@@ -40,7 +40,7 @@ describe('findTheOldest', () => {
     ]
     expect(findTheOldest(people).name).toBe('Ray');
   });
-  test.skip('finds the oldest person if the OLDEST is still living', () => {
+  test('finds the oldest person if the OLDEST is still living', () => {
     const people = [
       {
         name: "Carly",