Does HashTable maintains the insertion order?

Question

The following code gives me the output in the same order of insertion. I read the javadoc and they did not even talk about the insertion order. Can someone help me to get th

Answer 1

No, it does not. To preserve insertion order, instead use java.util.LinkedHashMap (javadoc).

Also, HashMap is now preferred over Hashtable, because Hashtable has unnecessary concurrency overhead. (See Differences between HashMap and Hashtable?.)