What are synchronized and volatile keywords in Java?

Can you explain the difference between synchronized and volatile in Java?

Sure! The 'synchronized' keyword is used to control access to a block of code or an object by multiple threads, ensuring that only one thread can execute it at a time. On the other hand, 'volatile' is used to indicate that a variable's value will be modified by different threads, ensuring that changes made by one thread are visible to others.

When should I use synchronized instead of volatile?

You should use 'synchronized' when you need to ensure that only one thread can access a block of code at a time, especially when multiple threads are modifying shared data. Use 'volatile' when you want to ensure visibility of changes to a variable across threads without needing to lock the entire block of code.

Can you give an example of when to use each?

Certainly! Use 'synchronized' when updating a shared counter to prevent race conditions. Use 'volatile' for a flag variable that indicates whether a thread should keep running or stop, ensuring all threads see the latest value.

What are the performance implications of using these keywords?

Using 'synchronized' can lead to performance overhead due to thread contention, while 'volatile' is lighter but doesn't provide atomicity. Choose based on your specific use case.