Add well known examples

tshemsedinov · tshemsedinov · commit 33595daf1b06 · 2019-03-19T15:28:03.000+02:00
diff --git a/JavaScript/4-well-known.js b/JavaScript/4-well-known.js
@@ -0,0 +1,41 @@
+'use strict';
+
+const persons = [
+  { name: 'Marcus Aurelius', city: 'Rome', born: 121 },
+  { name: 'Victor Glushkov', city: 'Rostov on Don', born: 1923 },
+  { name: 'Ibn Arabi', city: 'Murcia', born: 1165 },
+  { name: 'Mao Zedong', city: 'Shaoshan', born: 1893 },
+  { name: 'Rene Descartes', city: 'La Haye en Touraine', born: 1596 },
+];
+
+console.group('Sort strategy: descending by born year');
+{
+  const strategy = (a, b) => (a.born < b.born ? 1 : -1);
+  persons.sort(strategy);
+  console.table(persons);
+}
+console.groupEnd();
+
+console.group('Sort strategy: ascending by name alphabetically');
+{
+  const strategy = (a, b) => (a.name > b.name ? 1 : -1);
+  persons.sort(strategy);
+  console.table(persons);
+}
+console.groupEnd();
+
+console.group('Filter strategy: single word city name');
+{
+  const strategy = person => person.city.split(' ').length === 1;
+  const res = persons.filter(strategy);
+  console.table(res);
+}
+console.groupEnd();
+
+console.group('Reduce strategy: sum born years');
+{
+  const strategy = (acc, person) => acc + person.born;
+  const res = persons.reduce(strategy, 0);
+  console.table(res);
+}
+console.groupEnd();
