Remove live code & console.log, leave examples as comments (ProjectEuler, Recursive).

Project-Euler/Problem013.js

@@ -107,13 +107,11 @@ const numbers = [
   53503534226472524250874054075591789781264330331690
 ]
 
-const findFirstTenDigitsOfSum = () => {
-  const sum = numbers.reduce((prev, current) => {
+export const findFirstTenDigitsOfSum = (N = numbers) => {
+  const sum = N.reduce((prev, current) => {
     current += prev
     return current
   }, 0)
 
   return sum.toLocaleString('fullwide', { useGrouping: false }).split('').slice(0, 10).join('')
 }
-
-console.log(findFirstTenDigitsOfSum())

Project-Euler/Problem014.js

@@ -31,10 +31,10 @@ const getCollatzSequenceLength = (num, seqLength) => {
   }
 }
 
-const findLongestCollatzSequence = () => {
+export const findLongestCollatzSequence = (limit = 1_000_000) => {
   let startingPointForLargestSequence = 1
   let largestSequenceLength = 1
-  for (let i = 2; i < 1000000; i++) {
+  for (let i = 2; i < limit; i++) {
     const currentSequenceLength = getCollatzSequenceLength(i, 1)
     if (currentSequenceLength > largestSequenceLength) {
       startingPointForLargestSequence = i
@@ -43,5 +43,3 @@ const findLongestCollatzSequence = () => {
   }
   return startingPointForLargestSequence
 }
-
-console.log(findLongestCollatzSequence())

Project-Euler/Problem015.js

@@ -6,7 +6,7 @@ How many such routes are there through a 20×20 grid?
 
 // A lattice path is composed of horizontal and vertical lines that pass through lattice points.
 
-const latticePath = (gridSize) => {
+export const latticePath = (gridSize) => {
   let paths
   for (let i = 1, paths = 1; i <= gridSize; i++) {
     paths = paths * (gridSize + i) / i
@@ -14,4 +14,6 @@ const latticePath = (gridSize) => {
   // The total number of paths can be found using the binomial coefficient (b+a)/a.
   return paths
 }
-console.log(latticePath(20)) // output = 137846528820
+
+// > latticePath(20))
+// 137846528820

Project-Euler/Problem2.js

@@ -4,10 +4,9 @@ const PHI = (1 + SQ5) / 2 // definition of PHI
 
 // theoretically it should take O(1) constant amount of time as long
 // arithmetic calculations are considered to be in constant amount of time
-const EvenFibonacci = (limit) => {
+export const EvenFibonacci = (limit) => {
   const highestIndex = Math.floor(Math.log(limit * SQ5) / Math.log(PHI))
   const n = Math.floor(highestIndex / 3)
   return ((PHI ** (3 * n + 3) - 1) / (PHI ** 3 - 1) -
     ((1 - PHI) ** (3 * n + 3) - 1) / ((1 - PHI) ** 3 - 1)) / SQ5
 }
-console.log(EvenFibonacci(4e6)) // Sum of even Fibonacci upto 4 Million

Project-Euler/Problem4.js

@@ -2,7 +2,7 @@
 /* A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.
    Find the largest palindrome made from the product of two 3-digit numbers.
 */
-const largestPalindromic = (digits) => {
+export const largestPalindromic = (digits) => {
   let i
   let n
   let m
@@ -43,4 +43,4 @@ const largestPalindromic = (digits) => {
   return NaN // returning not a number, if any such case arise
 }
 
-console.log(largestPalindromic(3))
+

Project-Euler/Problem5.js

@@ -5,7 +5,7 @@ Smallest multiple
 What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?
 */
 
-const findSmallestMultiple = () => {
+export const findSmallestMultiple = () => {
   const divisors = [20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2]
   let num = 21
   let result
@@ -18,5 +18,3 @@ const findSmallestMultiple = () => {
 
   return result
 }
-
-console.log(findSmallestMultiple())

Project-Euler/Problem6.js

@@ -1,8 +1,6 @@
 // https://projecteuler.net/problem=6
 
-const num = 100 // number we are checking; change to 10 to check 10 from example
-
-const squareDifference = (num) => {
+export const squareDifference = (num = 100) => {
   let sumOfSquares = 0
   let sums = 0
   for (let i = 1; i <= num; i++) {
@@ -11,5 +9,3 @@ const squareDifference = (num) => {
   }
   return (sums ** 2) - sumOfSquares // difference of square of the total sum and sum of squares
 }
-
-console.log(squareDifference(num))

Project-Euler/Problem7.js

@@ -1,10 +1,7 @@
 // https://projecteuler.net/problem=7
 // My approach does not use the Sieve of Eratosthenes but that is another common way to approach this problem. Sieve of Atkin is another possibility as well.
 
-const num = 10001
-const primes = [2, 3, 5, 7, 11, 13] // given list of primes you start with
-
-const calculatePrime = (num) => {
+export const calculatePrime = (num = 10001, primes = [2, 3, 5, 7, 11, 13]) => {
   // Calculate each next prime by checking each number to see what it's divisible by
   let count = primes.length // count number of primes calculated
   let current = primes[count - 1] + 1 // current number being assessed if prime
@@ -27,5 +24,3 @@ const calculatePrime = (num) => {
   }
   return primes[num - 1]
 }
-
-console.log(calculatePrime(num))

Project-Euler/Problem9.js

@@ -12,7 +12,7 @@ Find the product abc.
 
 const isPythagoreanTriplet = (a, b, c) => Math.pow(a, 2) + Math.pow(b, 2) === Math.pow(c, 2)
 
-const findSpecialPythagoreanTriplet = () => {
+export const findSpecialPythagoreanTriplet = () => {
   for (let a = 0; a < 1000; a++) {
     for (let b = a + 1; b < 1000; b++) {
       for (let c = b + 1; c < 1000; c++) {
@@ -23,5 +23,3 @@ const findSpecialPythagoreanTriplet = () => {
     }
   }
 }
-
-console.log(findSpecialPythagoreanTriplet())