Create 2629-function-composition.js

Author: dmgodoy

javascript/2629-function-composition.js

@@ -0,0 +1,17 @@
+/**
+ * @param {Function[]} functions
+ * @return {Function}
+ */
+var compose = function (functions) {
+    return function (x) {
+        let ans = x;
+        for (fn of functions.reverse())
+            ans = fn(ans);
+        return ans;
+    }
+};
+
+/**
+ * const fn = compose([x => x + 1, x => 2 * x])
+ * fn(4) // 9
+ */