Project Euler problems (numbering) : follow naming convention.

Project-Euler/Problem003.js

@@ -0,0 +1,18 @@
+// https://projecteuler.net/problem=3
+
+export const largestPrime = (num = 600851475143) => {
+  let newnumm = num
+  let largestFact = 0
+  let counter = 2
+  while (counter * counter <= newnumm) {
+    if (newnumm % counter === 0) {
+      newnumm = newnumm / counter
+    } else {
+      counter++
+    }
+  }
+  if (newnumm > largestFact) {
+    largestFact = newnumm
+  }
+  return largestFact
+}