Comparing Functional and Object Oriented patterns in JavaScript

functional-task-list.js

var tasks = [];

function display() {
  var output = "";
  for(i=0; i < tasks.length; i++) {
    output += (i+1) + ". " + tasks[i] + "\n";
  }
  alert(output);
}

function get() {
  var taskDescription = prompt("Type your task");
  tasks.push(taskDescription);
  display();
}

get(); // get task 1
get(); // get task 2

module-style-task-list.js

var taskModule = (function () {
  
  var tasks = [];
  
  function displayTask() {
    var output = "";
    for(i=0; i < tasks.length; i++) {
      output += (i+1) + ". " + tasks[i] + "\n";
    }
    alert(output);
  }

  function getTask() {
    var taskDescription = prompt("Type your task");
    tasks.push(taskDescription);
    displayTask();
  }
  
  return {
    get: getTask
  };

})();

taskModule.get(); // get task 1
taskModule.get(); // get task 2

oo-task-list.js

function Task() {
  this.constructor.all.push(this);
}
Task.all = [];
Task.prototype.display = function () {
  var output = "";
  for(i=0; i < Task.all.length; i++) {
    output += (i+1) + ". " + Task.all[i].description + "\n";
  }
  alert(output);
};
Task.prototype.get = function () {
  var taskDescription = prompt("Type your task");
  this.description = taskDescription;
  this.display();
};

var task1 = new Task();
task1.get(); // get task 1
var task2 = new Task();
task2.get(); // get task 2