HashMap

Example:

var map = new HashMap();
  map.put("key1","Value1");
  map.put("key2","Value2");
  map.put("key3","Value3");
  map.put("key4","Value4");
  map.put("key5","Value5");
  alert("size："+map.size()+" key1："+map.get("key1"));
  map.remove("key1");
  map.put("key3","newValue");
  var values = map.values();
  for(var i in values){
      document.write(i+"："+values[i]+"   ");
  }
  document.write("<br>");
  var keySet = map.keySet();
  for(var i in keySet){
      document.write(i+"："+keySet[i]+"  ");
  }
  alert(map.isEmpty());