What is the use of @SuppressWarnings

Question

I didn't understand this feature of Java. I know it makes coding easier and sometimes looks neater, but what is the actual use of this? On contrary i feel, its better to display the warnings, as in future any one can refer them before making modifications to code. Does this @SuppressWarnings increases compliling efficiency OR is this according to any coding standards?

Answer 1

While programming you should watch out for compiler warnings and in best case compile your code with no warnings (and errors of course).

But sometimes you can't get rid of a warning and you KNOW the code is correct or can't be changed. Then you don't want to be bothered every time from the compiler that there is something wrong.

So you can suppress it with the command you mentioned.

Answer 2

Other answers already explained use cases of @SuppressWarnings a lot, but I want to emphasize the point that sometimes you absolutely need to use @SuppressWarnings to overcome limitations of the language itself, and in these cases use of @SuppressWarnings is absolutely legal.

In other cases use of @SuppressWarnings can be considered questionable, because in these cases you can always get rid of warnings by changing the code (though, obviously, it's not always acceptable).

Here are some common cases when you absolutely cannot get rid of warnings without @SuppressWarnings:

• Implementing an array-backed generic collection (since you cannot create a generic array)
• A Map from classes to their implementations (since you cannot assign different values of generic type parameter to different map entires)

Answer 3

When you are dealing with legacy code that does not support generics (Java <= 1.4) that is the only viable way of geting rid of cast warnings.