September 2017 Update

Task/Sum-and-product-of-an-array/JavaScript/sum-and-product-of-an-array-3.js

@@ -0,0 +1,19 @@
+(() => {
+    'use strict';
+
+    // sum :: (Num a) => [a] -> a
+    const sum = xs => xs.reduce((a, x) => a + x, 0);
+
+    // product :: (Num a) => [a] -> a
+    const product = xs => xs.reduce((a, x) => a * x, 1);
+
+
+    // TEST
+    // show :: a -> String
+    const show = x => JSON.stringify(x, null, 2);
+
+    return show(
+        [sum, product]
+        .map(f => f([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]))
+    );
+})();