added more comments and standardized code

Author: victorialo

Project-Euler/Problem7.js

@@ -1,30 +1,31 @@
 // 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;
-
-let primes = [2,3,5,7,11,13]; // given list of primes you start with
+const num = 10001
+const primes = [2, 3, 5, 7, 11, 13] // given list of primes you start with
 
 const calculatePrime = (num) => {
-  let count = primes.length; // count number of primes calculated
-  let current = primes[count-1] + 1; // current number being assessed if prime
+  // 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
   while (count < num) { // repeat while we haven't reached goal number of primes
     // go through each prime and see if divisible by the previous primes
-    let prime = false;
+    let prime = false
     primes.some((n, i) => {
       if (current % n === 0) {
-        return true;
+        return true
       }
-      if (i === count-1) {
-        prime = true;
+      if (i === count - 1) {
+        prime = true
       }
     })
-    if (prime) {
-      primes.push(current);
-      count += 1;
+    if (prime) { // if prime, add to prime list and increment count
+      primes.push(current)
+      count += 1
     }
-    current += 1;
+    current += 1
   }
-  return primes[num-1];
+  return primes[num - 1]
 }
 
-console.log(calculatePrime(num));
+console.log(calculatePrime(num))