text: /* Queues */
  
  function Queue () {
      let collection = [];
      this.print = function() {
          console.log(collection);
      };
      this.enqueue = function(element) {
          collection.push(element);
      };
      this.dequeue = function() {
          return collection.shift();
      };
      this.front = function() {
          return collection[0];
      };
      this.size = function() {
          return collection.length;
      };
      this.isEmpty = function() {
          return (collection.length === 0);
      };
  }
  
  const q = new Queue();
  q.enqueue('a');
  q.enqueue('b');
  q.enqueue('c');
  q.print();
  q.dequeue();
  console.log(q.front());
  q.print();
  
  
  function PriorityQueue () {
      const collection = [];
      this.printCollection = function() {
        (console.log(collection));
      };
      this.enqueue = function(element){
          if (this.isEmpty()){
              collection.push(element);
          } else {
              let added = false;
              for (let i=0; i<collection.length; i++){
                   if (element[1] < collection[i][1]){ //checking priorities
                      collection.splice(i,0,element);
                      added = true;
                      break;
                  }
              }
              if (!added){
                  collection.push(element);
              }
          }
      };
      this.dequeue = function() {
          const value = collection.shift();
          return value[0];
      };
      this.front = function() {
          return collection[0];
      };
      this.size = function() {
          return collection.length;
      };
      this.isEmpty = function() {
          return (collection.length === 0);
      };
  }
  
  const pq = new PriorityQueue();
  pq.enqueue(['Beau Caren', 2]);
  pq.enqueue(['Quincy Larson', 3]);
  pq.enqueue(['Ewa Meats', 1]);
  pq.enqueue(['Briana Swift', 2]);
  pq.printCollection();
  pq.dequeue();
  console.log(pq.front());
  pq.printCollection();
  