Atomic operations ensure correct program behavior by preventing data corruption.
Compound operations like count++ are not atomic because they involve multiple steps: reading, modifying, and writing back the value. In a multithreaded environment, these steps can be interleaved dangerously. For example, if two threads increment a shared counter simultaneously without atomicity, both might read the same initial value, increment it, and write back the same result, leading to data corruption. Using AtomicInteger provides methods like incrementAndGet() that ensure atomicity and prevent such issues.
Additional Notes
Why is it important for compound operations to be atomic in Java?