September 2017 Update

Task/Sum-of-squares/JavaScript/sum-of-squares-5.js

@@ -0,0 +1,20 @@
+(() => {
+    'use strict';
+
+    // squared :: Num a => a -> a
+    const squared = x => Math.pow(x, 2);
+
+    // sum :: (Num a) => [a] -> a
+    const sum = xs => xs.reduce((a, x) => a + x, 0);
+
+    // sumOfSquares :: Num a => [a] -> a
+    const sumOfSquares = xs => sum(xs.map(squared));
+
+    // sumOfSquares2 :: Num a => [a] -> a
+    const sumOfSquares2 = xs =>
+        xs.reduce((a, x) => a + squared(x), 0);
+
+    return [sumOfSquares, sumOfSquares2]
+        .map(f => f([3, 1, 4, 1, 5, 9]))
+        .join('\n');
+})();