Flatten array (#970)

recursion/js/flattenArray.js

@@ -0,0 +1,21 @@
+/*
+    Given a nested array the objective is to flatten it to a signle array in the same order it appaers
+    Sample i/p      : [1,2,[3,4,[5,6],7],8,9]
+    Expected o/p    : [1,2,3,4,5,6,7,8,9,] 
+*/
+
+var input = [1,2,[3,4,[5,6],7],8,9]
+var output = [];
+
+function flattenArray(input, output){
+  for(var i = 0; i < input.length; i++) {
+    if(Array.isArray(input[i])) {
+      flattenArray(input[i], output);
+    } else {
+      output.push(input[i]);
+    }
+  }
+};
+
+flattenArray(input, output);
+console.log(output);