Can you explain what is the difference between hashtable and hashmap

Question

Hi,

Actually I am confused what should I use for my case hashtable or hashmap?

I need to add null values as a key.

So can you explain which one should be perfect for my code?

Thank you

Answer 1

Hi,

1. Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.

2. Hashtable does not allow null keys or values. HashMap allows one null key and any number of null values.

3. One of HashMap's subclasses is LinkedHashMap, so in the event that you'd want a predictable iteration order (which is insertion order by default), you could easily swap out the HashMap for a LinkedHashMap. This wouldn't be as easy if you were using Hashtable.

I hope you clear with your doubt.

Thank you,