Also, which one offers better efficiency in non-threaded (single-threaded) applications?
In my experience, HashMap vs Hashtable really comes down to synchronization.
Hashtable is thread-safe because all its methods are synchronized, but that comes with a performance hit.
HashMap, on the other hand, is not synchronized and is much faster in single-threaded environments.
I always choose HashMap when I’m not dealing with concurrency because the overhead with Hashtable just isn’t worth it unless thread safety is a hard requirement.
I’ve used both over the years, and honestly, Hashtable feels pretty obsolete now.
With HashMap vs Hashtable, HashMap gives me better flexibility; it allows null keys and values, whereas Hashtable doesn’t.
Plus, HashMap integrates better with modern Java features like streams and lambda expressions.
For non-threaded apps, HashMap is just more efficient and readable.
If I need thread safety, I prefer ConcurrentHashMap anyway.
@keerti_gautam When I first transitioned an old system from Hashtable to HashMap, I noticed immediate performance improvements.
The big difference is how they handle synchronization. In hashmap vs hashtable, HashMap doesn’t lock every method, which gives it a big speed advantage in single-threaded applications.
If you ever need synchronization later, you can always wrap a HashMap using Collections.synchronizedMap() instead of defaulting to Hashtable.