Exception and Assertions

Question 1

Suppose you have to instantiate a scanner object, what is the syntax for the try-with-resource block?

Answer 1

try(Scanner consoleScanner = new Scanner(System.in)) {
..
}

Question 2

Can you provide try-with resources statements without any explicit catch or finally blocks?

Answer 2

Yes

Question 3

What is the requirements for a resource to be used with a try-with-resource statement?

Answer 3

That resource must implement java.lang.AutoCloseable interface

Question 4

If an assertion is false, what does it throw?

Answer 4

AssertionError, derived from Error

Question 5

How do you enable assertions for class/packages

?

Answer 5

To specify a class, use the class name. To specify the package name, use the package name followed by three dots …

java -ea:{Class} myPackage.MyProgram
java -ea:{package}… myPackage.MyProgram

• When you use package name in the ea/da flag, the flag applies to its sub packages as well