SCJP Basic 5

Question 1

Which of the following correctly describes an abstract class in Java?

Accepted Answer

It may contain abstract and concrete methods

Answer

An abstract class can have a mix of abstract (no body) and concrete (with body) methods.

Question 2

What is the result of comparing two String objects with == in Java?

Accepted Answer

Compares object references, not content

Answer

== on objects checks reference equality (same memory address), not the content of the strings.

Question 3

Which of the following is true about a Java interface before Java 8?

Accepted Answer

All methods are implicitly public and abstract

Answer

Prior to Java 8, interface methods were implicitly public and abstract and could not have implementations.

Question 4

What is the scope of a variable declared inside a for-loop initializer?

Accepted Answer

Only within the for-loop block

Answer

A variable declared in a for-loop initializer is scoped to the for-loop block only.

Question 5

Which of the following statements about Java arrays is true?

Accepted Answer

Arrays in Java are objects stored on the heap

Answer

Java arrays are objects allocated on the heap with a fixed size determined at creation.

SCJP - Sun Certified Java Programmer Practice Test