While studying Java Collections , i cannot understand the main difference between HashMap and LinkedHashMap ? From what i understand The below given codes, HashMap does not maintain insertion order, but LinkedHashMap does ? Is this the only difference.
Output : a,b,c
Secondly how do you iterate over the values in a HashMap and HashTable ? Are we supposed to reuse the key returned by the keySet to get the value of the key ? Secondly a Set does not allow duplicates, so what about duplicate keys ?