added prettier config

Author: varun93

array-sum.js

@@ -0,0 +1,20 @@
+const findArraySum = (array, index, sum) => {
+  if (index === array.length) {
+    return sum;
+  }
+
+  let element = array[index];
+
+  if (Array.isArray(element)) {
+    element = findArraySum(element, 0, 0);
+  }
+
+  sum += element;
+
+  return findArraySum(array, index + 1, sum);
+};
+
+/* 
+example input
+const array = [1,[11,42,[8, 1], 4, [22,21]]]; 
+*/