My first attempt at Problem 8, Project Euler

project-euler-problem-8.js

/**
 * This is my first attempt at Problem 8 (Largest product in a series), Project Euler.
 * @see https://projecteuler.net/problem=8
 */

const numbers = `73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450`.split("").filter(v => /\S/.test(v)).map(Number);

const sequenceLength = 13;
const sum = (n, m) => n + m;
const product = (n, m) => n * m;

let maxStartIndex = 0;
let maxProduct = 0;

for (let i = 0; i < numbers.length - sequenceLength; ++i) {
  const seq = numbers.slice(i, i + sequenceLength);
  if (seq.includes(0)) {
    continue;
  }
  const newMax = seq.reduce(product);
  if (newMax > maxProduct) {
    maxProduct = newMax;
    maxStartIndex = i;
  }
}

console.log(maxProduct);