// https://www.freecodecamp.org/learn/coding-interview-prep/data-structures/create-a-queue-class

function Queue() {
  var collection = [];
  this.print = function () {
    console.log(collection);
  };
  // Only change code below this line
  this.enqueue = function (elem) {
    collection.push(elem);
  };
  this.dequeue = function () {
    return collection.shift();
  };
  this.front = function () {
    return collection[0];
  };
  this.size = function () {
    return collection.length;
  };
  this.isEmpty = function () {
    return !collection.length;
  };
  // Only change code above this line
}