Sieve of Eratosthenes ES6 code added

Author: me-shaon

Number Theory/GCD/es6/gcd.js

@@ -1,4 +1,4 @@
-/* Greatest Common Divisor (GCD) Finding in JavaScript */
+/* Greatest Common Divisor (GCD) Finding in JavaScript (ES6) */
 
 const gcd = (a, b) => {
 	while (true) {

Number Theory/LCM/es6/lcm.js

@@ -1,4 +1,4 @@
-/* Least Commond Multiple (LCM) Finding in JavaScript */
+/* Least Commond Multiple (LCM) Finding in JavaScript (ES6) */
 const gcd = require('./gcd');
 
 /*

Number Theory/Sieve of Eratosthenes/es6/sieve.js

@@ -0,0 +1,27 @@
+/* Sieve of Eratosthenes implementation in JavaScript(ES6) */
+
+// This function will return the list of Primes less than given 'limit'
+module.exports.sieve = (limit) => {
+    //As we know only 'even' prime number is 2, we are marking each of the 'even' index as false
+    const sieve = new Array(limit).fill(0).map((elem, index) => ((index % 2) === 1));  //if the index is odd return true, otherwise
+
+    sieve[1] = false;
+    sieve[2] = true;
+
+    const sqrtLimit = Math.sqrt(limit);
+
+    for (var i=3; i<=sqrtLimit; i+=2) {
+        if (sieve[i] === true) {
+            for (var k=i*i; k<=limit; k+=i)
+                sieve[k] = false;
+        }
+    }
+
+    const primes = [];
+    sieve.forEach((value, key) => {
+      if (value)
+        primes.push(key);
+    });
+
+    return primes;
+}

Number Theory/Sieve of Eratosthenes/es6/test.js

@@ -0,0 +1,4 @@
+const { sieve } = require('./sieve');
+
+/************ Testing Sieve of Eratosthenes Code ***************/
+console.log(sieve(100));

Number Theory/Sieve of Eratosthenes/sieve.js

@@ -1,8 +1,7 @@
 /* Sieve of Eratosthenes implementation in JavaScript */
 
+// This function will return the list of Primes less than given 'limit'
 function sieve(limit) {
-    var sieve = [],
-        primes = [];
 
     var sieve = Array.apply(null, Array(limit)).map(function (elem, index) {
         //As we know only 'even' prime number is 2, we are marking each of the 'even' index as false
@@ -21,6 +20,8 @@ function sieve(limit) {
         }
     }
 
+    var primes = [];
+
     sieve.forEach(function (value, key) {
         if (value)
             primes.push(key);