APCSA Barrons Practice exam 2

A large java program was tested extensively, and no errors were found. What can be concluded?

• All of the preconditions in the program are correct

• All of the postconditions in the program are correct

• the program may have bugs

• the program has no bugs

• every method in the program may safely be used in other programs

Refer to the incrementWage method. Which of the following is a correct /*implementation of incrementWage*/?

• return hourlyWage + amt;

• return getHourlyWage() + amt;

• hourlywage += amt;

• getHourlyWage() += amt;

• hourlyWage = amt;

Consider the method changeUnionStatus. Which is a correct /*implementation of changeUnionStatus*/?

• I only

• II only

• III only

• I and II only

• I, II, and III only

A client method computePay will return a worker’s pay based on the number of hours worked.

Which replacement for /* code*/ is correct?

• return hourlyWage * hours;

• return getHourlyWage()*hours

• return w.getHourlyWage () * hours;

• return w.hourlyWage * hours;

• return w.getHourlyWage() * w.hours;

Consider this program segment. You may assume that word List has been declared as ArrayList<String>.

What is the maximum number of times that SHORT WORD can be printed?

• 3

• 4

• wordList.size()

• wordList.size() -1

• s.length()

Refer to the following method.

What value does mystery(4) return?

• 3

• 9

• 12

• 27

• 81

Refer to the following declarations:

Which of the following correctly assigns the elements of the colors array to colorList? The final ordering of colors in colorList should be the same as in the colors array.

• I only

• II only

• III only

• II and III only

• I,II, and III

Often the most efficient computer algorithms use a divide-and-conquer approach, for example, one in which a list is repeatedly split into two pieces until a desired outcome is reached. Which of the following use a divide-and-conquer approach?

• I only

• II only

• III only

• I and III only

• I, II, and III

An Insect class is to be written, containing the following data fields: age, which will be initialized to 0 when an Insect is constructed. nextAvailableID, which will be initialized to 0 outside the constructor and incremented each time an Insect is constructed. idNum, which will be initialized to the current value of nextAvailableID when an Insect is constructed. position, which will be initialized to the location in a garden where the Insect is placed when it is constructed. direction, which will be initialized to the direction the Insect is facing when placed in the garden.

Which variable in the Insect class should be static?

• age

• nextAvailableID

• idNum

• position

• direction

Which of the following correctly creates a Customer object c?

I Address a = new Address("125 Bismark St", "Pleasantville", "NY", 14850); Customer c = new Customer("Jack Spratt", "747-1674", a, 7008);

II Customer c = new Customer("Jack Spratt", "747-1674", "125 Bismark St, Pleasantville, NY 14850", 7008);

III Customer c = new Customer("Jack Spratt", "747-1674", new Address("125 Bismark St", "Pleasantville", "NY", 14850), 7008);

• I only

• II only

• III only

• I and II only

• I and III only