diff --git a/getPositiveSum.test.js b/getPositiveSum.test.js
new file mode 100644
index 00000000..e7269c5b
--- /dev/null
+++ b/getPositiveSum.test.js
@@ -0,0 +1,4 @@
+const getPositiveSum = require("./index");
+test("Returns some of posetives", () => {
+    expect(getPositiveSum()).toBe(18);
+});
\ No newline at end of file
diff --git a/index.js b/index.js
index ff28a6f9..f6db8364 100644
--- a/index.js
+++ b/index.js
@@ -1,22 +1,41 @@
-class NumberArray {
-  constructor(numbers) {
-    this.numbers = numbers;
-  }
+// class NumberArray {
+//   constructor(numbers) {
+//     this.numbers = numbers;
+//   }
+
+//   getPositiveSum() {
+//     let sum = 0;
+//     for (let number of this.numbers) {
+//       if (number > 0) {
+//         sum += number;
+//       }
+//     }
+//     return sum;
+//   }
+// }
+
+// const numbers = [2, -4, 6, -8, 10, -12];
+// const numberArray = new NumberArray(numbers);
+// const positiveSum = numberArray.getPositiveSum();
+
+// Input: [2, -4, 6, -8, 10, -12]
+// Output: 18
 
-  getPositiveSum() {
-    let sum = 0;
-    for (let number of this.numbers) {
-      if (number > 0) {
-        sum += number;
-      }
+getPositiveSum = () => {
+  let sum = 0;
+  for (let number of numbers) {
+    if (number > 0) {
+      sum += number;
     }
-    return sum;
   }
+  return sum;
 }
-
+module.exports = getPositiveSum;
 const numbers = [2, -4, 6, -8, 10, -12];
-const numberArray = new NumberArray(numbers);
-const positiveSum = numberArray.getPositiveSum();
+console.log(getPositiveSum(numbers));
 
-// Input: [2, -4, 6, -8, 10, -12]
-// Output: 18
+
+// //Functions do specific things, classes are specific things.
+// Classes often have methods, which are functions that are associated with
+// a particular class, and do things associated with the thing that the class is -
+// but if all you want is to do something, a function is all you need.