function Queue(){
	var items = [];
  var p = "";
  this.enqueue = function(element){
  	items.push(element);
  }
  this.dequeue = function(){
  	items.shift();
  }
  this.front = function(){
  	if(items.length === 0){
    	return 'Null Array';
    }else{
    	return items[0];
    }
  }

  this.isEmpty = function(){
  	if(items.length === 0){
    	return false;
    }else{
    	return true;
    }
  }

  this.size = function(){
  	return items.length;
  }
  this.print = function(){
  	for (var i = 0;i < items.length;i++){
   		p += items[i];
    }
    return p;
  }
}

var q = new Queue();

q.enqueue(1);
q.enqueue(2);
q.enqueue(3);
console.log(q.print());
q.dequeue();
console.log(q.print());