SCJP Sun Certified Java Programmer 2

Question 1

What is the output of: int x = 5; System.out.println(x++ + ++x);

Accepted Answer

12

Answer

x++ returns 5 (then x becomes 6), ++x increments x to 7 and returns 7, so 5+7=12.

Question 2

Which of the following correctly declares a two-dimensional array in Java?

Accepted Answer

int[][] arr = new int[3][];

Answer

Java allows the first dimension to be specified without the second in a 2D array declaration.

Question 3

Which access modifier allows a member to be accessible only within its own package and by subclasses?

Accepted Answer

protected

Answer

The protected modifier allows access within the same package and by subclasses in any package.

Question 4

What happens when a class implements two interfaces that declare the same default method without overriding it?

Accepted Answer

A compilation error occurs

Answer

Java requires the class to override the conflicting default method; otherwise a compile-time error occurs.

Question 5

Which statement about the String.intern() method is correct?

Accepted Answer

It returns a canonical representation from the string pool

Answer

String.intern() returns the canonical instance from the string pool, or adds it if absent.

SCJP - Sun Certified Java Programmer Practice Test