Simple Queue using javascrip

var Queue = (function() {
 var items = [];
 var Queue = function() {
  return this;
 };
 var is_array = function (value) {
  return value && typeof value === 'object' && typeof value.length === 'number' && typeof value.splice === 'function' && !(value.propertyIsEnumerable('length'));
 };
 Queue.prototype = {
  isEmpty : function () {
   return items.length === 0;
  },
  empty : function() {
   items = [];
   return this.isEmpty();
  },
  enqueue : function (data) {
   if (is_array(data)) {
    if (items.length == 0) {
     items = data;
    } else {
     for(var i in data) {
      items.push(data[i]);
     }
    }
   } else {
    items.push(data);
   }
   return this;
  },
  dequeue : function () {
   return items.shift();
  }
 };
 return new Queue();
})();

Usage:

var data = [];
Queue.enqueue(data);
if (Queue.isEmpty() === false) {
 // do it
} else {
 // Queue is empty !
}
data = {a : 1, b : 2 };
Queue.enqueue(data);
if (Queue.isEmpty() === false) {
 // do it
} else {
 // Queue is empty !
}