Deck 11: Object-Oriented Programming and Arrays

Question 1

Typically, what's the first thing you should do you in a subclass constructor?

A) Initialize the properties to 0.
B) Call the superclass constructor with this(arguments);.
C) Call the superclass constructor with super(arguments);.

Answer 1

C

Question 2

Suppose that you have a class named Student with a method named payFees and that you have instantiated an object named student. Which of the following is a proper call to the payFees method?

A) payFees();
B) student.payFees();
C) Student.payFees();

Answer 2

B

Question 3

The Array object's concat method returns a new array that is formed by concatenating the argument array to the end of the calling object array.

Answer 3

True

Question 4

An object has properties and methods. It is the properties that provide the interface with the outside world.

Question 5

OOP stands for ____________________.

Question 6

If the following code executes, what message displays in the resulting dialog box?
var x = 3.5;
alert(x > 3 ? x + 1 : x - 1);

Question 7

Why might it be appropriate for a button's onclick event-handler function to call its event object's stopPropagation method?

Question 8

Provide code that instantiates an array named carMakes such that the new array contains "Ford" and "Honda".

Question 9

Sort the following three strings so they are in ascending lexicographical order (words that are considered less than other words should be at the left).
"aardvark", "African polecat", "AARP"

Question 10

What is a two-dimensional array?

Question 11

The formal term for creating an object is:

A) objectification.
B) creation.
C) instantiation.

Question 12

What is the difference between a method heading and a function heading?

A) A method heading uses the word <code>method</code> at the left.
B) A function heading uses the word <code>function</code> at the left.
C) A method heading includes parameters and a function heading provides arguments.
D) A function heading includes parameters and a method heading provides arguments.

Question 13

If you declare a variable with <code>var</code>, but do not initialize it to a value, what will the variable contain?

A) <code>undefined</code>
B) <code>null</code>
C) 0

Question 14

Suppose an <code>onclick</code> event-handler function includes an <code>e</code> parameter for its passed-in event object. What code could be used to access the mouse pointer's x coordinate position?

A) <code>xValue</code>
B) <code>e.clientX</code>
C) <code>e.getXCoordinate();</code>

Question 15

Using the formal JavaScript inheritance terms, which of the following is true?

A) A subclass inherits from a superclass.
B) A superclass inherits from a subclass.
C) A generic class inherits from a specific class

Question 16

A class property is associated with a class as a whole, not with an individual instance of a class.

Question 17

To call a regular method, you preface the method name with an object and a dot. The object is referred to as a cotterized object.

Question 18

To emulate a class with legacy code, you implement a function whose name serves as a class name, and that function then serves as a constructor.

Question 19

Polymorphism refers to a variable's ability to change its type from a string to a number.

Question 20

A(n) __________ is a special method that gets called when there is an attempt to create an object.

Question 21

To sort an array of objects, you need to define a comparison function. The comparison function:

A) uses lexicographical ordering to perform the sort operation.
B) uses standard numerical ordering to perform the sort operation.
C) receives two elements from the array and returns a negative number, zero, or a positive number.
D) receives two elements from the array and returns true if the two elements should be swapped.

Question 22

If you would like to sort an array of date values, you should do which of the following?

A) Store the dates as strings because strings can be sorted more effectively than Date objects.
B) Store the dates as Date objects because Date objects can be sorted more effectively than strings.
C) Write an algorithm that parses date strings into their month, day, and year parts.

Question 23

The switch statement is most similar to which of the following?

A) "if by itself" form of the if statement
B) "if, else if " form of the if statement
C) while loop
D) do loop

Question 24

Suppose you have a subclass Truck, a superclass Vehicle, and a property in Vehicle named year. How can a method in Truck access the year property?

A) year
B) this.year
C) super.year
D) Vehicle.year

Question 25

When a function is called by another function (as opposed to when a function is called by an event handler attribute like onclick), the called function is known as a helper function.

Question 26

Legacy code is code that has improved over time to the point where it is now considered an exemplar of what good code should look like.

Question 27

The ______ method searches for a specified value within the calling object array's elements. It returns the index of the first element that holds the value.

Question 28

For the switch statement, if you need to do something special when there are no case constants that match the controlling expression's value, then you should use the keyword ______ at the bottom of the switch statement to handle that situation.

Question 29

To implement a subclass, you need to append the keyword ______ and then the superclass name to the end of the subclass's heading.

Question 30

UML stands for Unified __________ Language.