Merge pull request #264 from arjunmahishi/armstrong

Snippet for checking armstrong number

snippets/isArmstrongNumber.md

@@ -0,0 +1,13 @@
+### isArmstrongNumber
+
+Checks if the given number is an armstrong number or not.
+
+Convert the given number into array of digits. Use `Math.pow()` to get the appropriate power for each digit and sum them up. If the sum is equal to the number itself, return `true` otherwise `false`.
+
+```js
+const isArmstrongNumber = digits => 
+  ( arr => arr.reduce( ( a, d ) => a + Math.pow( parseInt( d ), arr.length ), 0 ) == digits ? true : false )( ( digits+'' ).split( '' ) );
+// isArmstrongNumber(1634) -> true
+// isArmstrongNumber(371) -> true
+// isArmstrongNumber(56) -> false
+```