Throw exception inside catch clause

Question

I have two snippet of code :

class PreciseRethrow {
public static void main(String[] str) {
    try {
        foo();
    } catch (NumberFormatException ife)          


        

Answer 1

You are attempting to throw an Exception, however you declare that you will throw a NumberFormatException, which is a subtype of Exception. All NumberFormatExceptions are Exceptions, however not all Exceptions are NumberFormatException, so it is not allowed. In the first example however, although you are catching an Exception, the compiler and IDE know that it will only ever be a NumberFormatException, which is safe.