--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sample/nashorn/array_mapreduce.js	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Usage: jjs array_mapreduce.js
+
+// Many Array.prototype functions such as map,
+// filter, reduce, reduceRight, every, some are generic.
+// These functions accept ECMAScript array as well as
+// many array-like objects including java arrays.
+// So, you can do map/filter/reduce with Java streams or
+// you can also use Array.prototype functions as below.
+// See also http://en.wikipedia.org/wiki/MapReduce
+
+var DoubleArray = Java.type("double[]");
+var StringArray = Java.type("java.lang.String[]");
+
+var map = Array.prototype.map;
+var filter = Array.prototype.filter;
+var reduce = Array.prototype.reduce;
+
+var jarr = new StringArray(5);
+jarr[0] = "nashorn";
+jarr[1] = "ecmascript";
+jarr[2] = "javascript";
+jarr[3] = "js";
+jarr[4] = "scheme";
+
+// sum of word lengths
+print("Sum word length:",
+    reduce.call(
+        map.call(jarr, function(x) x.length),
+        function(x, y) x + y)
+);
+
+// another array example involving numbers
+jarr = new DoubleArray(10);
+// make random array of numbers
+for (var i = 0; i < jarr.length; i++)
+    jarr[i] = Math.random();
+
+var forEach = Array.prototype.forEach;
+// print numbers in the array
+forEach.call(jarr, function(x) print(x));
+
+// print sum of squares of the random numbers
+print("Square sum:",
+    reduce.call(
+        map.call(jarr, function(x) x*x),
+        function(x, y) x + y)
+);