Certified Java Programmer Mock Exam

Question 1

Which of the following are true statements?

a.	Encapsulation is a form of data hiding.
b.	A tightly encapsulated class is always immutable.
c.	Encapsulation is always used to make programs run faster.
d.	Encapsulation helps to protect data from corruption.
e.	Encapsulation allows for changes to the internal design of a class while the public interface remains unchanged.

Question 2

Which of the following are true statements?

a.	A top-level class can not be called "tightly encapsulated" unless it is declared private.
b.	Encapsulation enhances the maintainability of the code.
c.	A tightly encapsulated class allows fast public access to member fields.
d.	A tightly encapsulated class allows access to data only through accessor and mutator methods.
e.	Encapsulation usually reduces the size of the code.
f.	A tightly encapsulated class might have mutator methods that validate data before it is loaded into the internal data model.

Question 3

A class can not be called "tightly encapsulated" unless which of the following is true?

a.	The class is declared final.
b.	All local variables are declared private.
c.	All method parameters are declared final.
d.	No method returns a reference to any object that is referenced by an internal data member.
e.	None of the above

Question 4

A class can not be called "tightly encapsulated" unless which of the following is true?

a.	All of the methods are declared private.
b.	All of the methods are synchronized.
c.	All local variables are declared final.
d.	The class is a direct subclass of Object.
e.	Accessor methods are used to prevent fields from being set with invalid data.
f.	None of the above

Question 5

A class can not be called "tightly encapsulated" unless which of the following are true?

a.	The data members can not be directly manipulated by external code.
b.	The class is declared final.
c.	It has no public mutator methods.
d.	The superclass is tightly encapsulated.

Question 6

A class can not be called "tightly encapsulated" unless which of the following is true?

a.	The class is a nested class.
b.	The constructors are declared private.
c.	The mutator methods are declared private.
d.	The class implements the Encapsulated interface.
e.	None of the above

Question 7

A class can not be called "tightly encapsulated" unless which of the following is true?

a.	All member fields are declared final.
b.	The class is not anonymous.
c.	The internal data model can be read and modified only through accessor and mutator methods.
d.	The class is an inner class.
e.	None of the above

Question 8

class GFC500 {private String name;}
class GFC501 {
  private String name;
  private void setName(String name) {this.name = name;}
  private String getName() {return name;}
}
class GFC502 {
  private String name;
  public void setName(String name) {this.name = name;}
  public String getName() {return name;}
}

Which class is not tightly encapsulated?

a.	GFC501
b.	GFC502
c.	GFC503
d.	None of the above

Question 9

class GFC505 extends GFC504 {
  public void setName(String name) {this.name = name;}
  public String getName() {return name;}
}
class GFC504 extends GFC503 {
  private void setName(String name) {this.name = name;}
  private String getName() {return name;}
}
class GFC503 {String name;}

Which class is tightly encapsulated?

a.	GFC503
b.	GFC504
c.	GFC505
d.	None of the above

Question 10

class GFC506 {private String name;}
class GFC507 extends GFC506 {
  String name;
  public void setName(String name) {this.name = name;}
  public String getName() {return name;}
}
class GFC508 extends GFC506 {
  private String name;
  public GFC508(String name) {setName(name);}
  public void setName(String name) {this.name = name;}
  public String getName() {return name;}
}

Which class is not tightly encapsulated?

a.	GFC506
b.	GFC507
c.	GFC508
d.	None of the above