SCJP Sun Certified Java Programmer 5

Question 1

Which of the following correctly describes the behavior of the finally block?

Accepted Answer

It always executes unless System.exit() is called

Answer

The finally block always executes after try/catch unless the JVM is terminated via System.exit().

Question 2

What is the default value of an instance variable of type boolean in Java?

Accepted Answer

false

Answer

The default value for an instance boolean variable is false in Java.

Question 3

Which interface must be implemented for a class to be used with the Collections.sort() method without a Comparator?

Accepted Answer

Comparable

Answer

A class must implement Comparable and its compareTo() method to support natural ordering with Collections.sort().

Question 4

What happens if you call Thread.sleep() with a negative value?

Accepted Answer

An IllegalArgumentException is thrown

Answer

Thread.sleep() throws IllegalArgumentException if the millisecond value is negative.

Question 5

In Java generics, what does the wildcard '? extends T' indicate?

Accepted Answer

Any type that is a subtype of T or T itself

Answer

'? extends T' is an upper-bounded wildcard accepting T or any subclass of T.

SCJP - Sun Certified Java Programmer Practice Test