Exception Handling and Assertions Flashcards

Which of the following correctly describes the difference between Error and Exception in Java?

Answer: Error represents serious JVM problems not meant to be caught; Exception represents recoverable conditions

Error represents serious problems like OutOfMemoryError that applications typically cannot recover from, while Exception represents conditions applications should handle.

In a multi-catch block `catch (IOException | SQLException e)`, what is the type of `e`?

Answer: The common supertype of both exceptions

In a multi-catch, the variable type is the most specific common supertype of all the listed exception types.

What happens when an assert statement's boolean expression is `false` and assertions are enabled?

Answer: It throws AssertionError

When an assertion fails (expression is false) and assertions are enabled, the JVM throws an AssertionError.

Which statement about try-with-resources and explicit finally blocks is correct in Java 9+?

Answer: finally blocks can coexist with try-with-resources and run after resources are closed

A try-with-resources can have an explicit finally block, which runs after all resources have been automatically closed.

What is printed by: `int x = 0; try { x = 1; return x; } finally { x = 2; System.out.print(x); }`?

Answer: 2

The finally block executes before the return completes, so x=2 is assigned and printed as '2', though the method returns 1.

Which of the following is true about declaring assertions in class static initializers?

Answer: Assertions in static initializers use system assertions flags (-esa)

Assertions in static initializers of system classes are controlled by the -esa (enable system assertions) flag, separate from -ea.

What is the result when a variable declared in try-with-resources is referenced after the try block?

Answer: Compilation error — scope is limited to the try block

Variables declared in the resource specification of try-with-resources are scoped to the try block and cannot be accessed outside it.