This is the most important difference between the two. HashMap is non-synchronized and not thread-safe. So what is meant by non-synchronized? It means if multiple programs simultaneously access HashMap, it keeps on updating. Now let's say there are five threads working on HashMap. That means five different programs or threads can access HashMap at the same time, which means there is no synchronization. But in HashTable, if one program is accessing HashTable, the other program needs to wait until the first program releases the HashTable resources. That's the major difference. On the other hand, HashTable is thread-safe and synchronized. When should you use HashMap? If your application does not require a multithreading ...
Synchronized or thread-safe
Get Hands-On Automation Testing with Java for Beginners now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.