Question

The java documentation says that it’s mandatory for a checked exception to specify an handler that can “catch” the exception or to throws it in the method declaration.
But, if i do, for example:

public class DivZero{
 public static void main(String[] args){
   int a=10;
   int[] b={1,2,3,4,0};
   for (int i=0;i<b.length;i++){
    System.out.println(a/b[i]);
   }
 }
}

It works fine also without “try-catch” or “throws” declaration. It throws a java.lang.ArithmeticException. So, it’s not mandatory? The compiler implicitly throws the suitable Java “Throwable” class in the same way. It’s so?

Answer 1

ArithmeticException extends RuntimeException thus it is not a checked exception. Checked exceptions are the ones inheriting from Exception but not from RuntimeException.

Quoting JLS, 11.1.1. The Kinds of Exceptions:

[…] checked exception classes are all subclasses of Throwable other than RuntimeException and its subclasses and Error and its subclasses.