What is the difference between const and volatile in C++?

What is the difference between const and volatile in C++?

In C++, const indicates that a variable's value cannot be changed after initialization, while volatile tells the compiler that a variable may be changed by external factors, preventing optimization.

Can you give me an example of when to use each?

Sure! Use const for values that should remain unchanged, like configuration settings. Use volatile for variables that can be modified by hardware or other threads, like a flag in a multi-threaded application.

What happens if I use them incorrectly?

Using const incorrectly can lead to unintended modifications, while misusing volatile can cause the compiler to optimize away necessary reads or writes, leading to unpredictable behavior.

Are there any performance implications?

Yes, using volatile can prevent certain optimizations, potentially leading to slower performance. const generally has no negative performance impact.