Difference Hashmap and Concurrent Hashmap

Question

Accepted Answer

HashMap is not thread-safe, while ConcurrentHashMap allows multiple threads to read and write concurrently.

HashMap is not synchronized and not thread-safe, while ConcurrentHashMap is synchronized and thread-safe.
ConcurrentHashMap allows multiple threads to read and write concurrently without any external synchronization, while HashMap requires external synchronization for concurrent access.
ConcurrentHashMap achieves higher concurrency by dividing the map into segments, allowing multiple threads to operate on different segments simultaneously.
Example: HashMap vs ConcurrentHashMap - HashMap can lead to ConcurrentModificationException if modified during iteration, while ConcurrentHashMap allows safe iteration even during modifications.

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