Please confirm that is your real name, or you will have to change it to conform with the naming policy.
Find the Map interface (and also Map.Entry) in the API and read it. A HashMap is made with an array, default size 16, and a load factor, default 0.75f (75%); whenever the number of entries is greater than load factor * size (starts at 12) the array is replaced by one double the size and its contents redistributed. The contents of the array are Map.Entry objects with a "K" (key) object and a "V" (value) object; their location is determined by key.hashCode() & (size - 1). Now you know enough to be able to set up a HashMap yourself, if you insist on "reinventing the wheel." [ June 26, 2008: Message edited by: Campbell Ritchie ]