Deminem · March 19, 2017 06:47 · Mar 19, 2017
diff --git a/sample.js b/sample.js
@@ -0,0 +1,58 @@
+(function() {
+  'use strict';
+
+  // create a person
+  function Person(name, ranking) {
+    this.name = name;
+    this.ranking = ranking;
+    this.toString = function() {
+      return '[' + this.name + ' ' + this.ranking + ']';
+    }
+  }
+
+  // sort by given property
+  Array.prototype.sortBy = function(prop) {
+    return this.slice(0).sort(function(o1, o2) {
+      if (o1[prop] > o2[prop]) {
+        return 1;
+      } else if (o1[prop] < o2[prop]) {
+        return -1;
+      }
+      return 0;
+    });
+  };
+
+  // calculate the average for given property i.e number
+  Array.prototype.average = function(prop) {
+    var average = 0;
+    this.forEach(function(obj) {
+      if (typeof obj[prop] === 'number') {
+        average += obj[prop];
+      }
+    });
+    return average;
+  };
+
+  // print the array
+  Array.prototype.print = function() {
+    return this.slice(0).toString();
+  };
+
+  // create the person object array
+  var personItems = [
+    new Person('John', 32), 
+    new Person('Martin', 18),
+    new Person('Steve', 26)
+  ];
+
+  // sort array w.r.t age and name
+  var sortByName = personItems.sortBy('name');
+  var sortByAge = personItems.sortBy('ranking');
+  var average = personItems.average('ranking');
+
+  // print the output on console
+  console.log('SortBy Name: ', sortByName.print());
+  console.log('SortBy Age: ', sortByAge.print());
+  console.log('Average Ranking: ', average);
+
+})();