ArrayList
For-Each Loop
Basics Classes
Constructors
Static Vs. Instance
100
When should you use an ArrayList?
A. When storing objects and primitives
B. When you need to use a standard for loop
C. When storing objects
D. When storing primitive
E. None of the items listed.
What is
C. When storing objects
100
You need to process an ArrayList and remove several elements in the list. Which loop is most appropriate?
A. for loop
B. All loops will work equally.
C. None of the items listed.
D. for-each loop
E. You cannot remove elements from an ArrayList.
What is
A. for loop
100
Which of the following statements about classes is NOT true?
A. Classes hold more than one piece of data at a time.
B. Classes hold only one piece of data at a time.
C. Classes can hold data of different types.
D. Classes have built in methods, or “tools”.
E. Users can create their own classes.
What is
B. Classes hold only one piece of data at a time.
100
Which of the following is NOT true about constructors?
A. Constructors have the same name as the class.
B. Constructors can have parameters.
C. Constructors are declared using the void keyword.
D. Constructors never have a void or return type.
What is
C. Constructors are declared using the void keyword.
100
Which of the following is true about static variables?
A. Static variables are shared among all instances of a class.
B. Static variables cannot be initialized in a constructor.
C. Static variables must be declared final.
D. Static variables can only be accessed by static methods.
What is
A. Static variables are shared among all instances of a class.
200
Which of the following is NOT true bout ArrayList objects?
A. ArrayList is a class data type.
B. Methods for insertion and deletion are built into the class.
C. ArrayList objects can only hold class type data.
D. They can be resized.
E. ArrayList objects can hold primitive type data.
What is
E. ArrayList objects can hold primitive type data.
200
What can be used to replace /* expression */ so that getTotalChars returns the total number of characters in all the Strings in words?
What is
s.length();
200
Class data types include variables and ______.
A. methods
B. objects
C. constructors
D. references
E. data
What is
A. methods
200
The ______ keyword creates an object in memory and assigns the memory reference to the variable.
A. public
B. instantiate
C. private
D. static
E. new
What is
E. new
200
Instance variables are variables whose value are specific to an instance of a class.
A. True
B. False
What is
A. True
300
What is output by this code?
What is
[shirt, sock, sweater, shorts]
300
Write a loop that will correctly print every element of nums which is greater than 10, but none of the other integers contained in nums?
What is
300
All instance variables should be declared as _______
A. primitives
B. objects
C. arrays
D. public
E. private
What is
E. private
300
What is true about constructor?
A. It can contain return type
B. It can take any number of parameters
C. It can have any non access modifiers
D. Constructor cannot throw an exception
What is
B. It can take any number of parameters
300
In a gas station class, which of the following variables would be static?
A. Customer bill
B. Gas Price
C. Customer
D. Vehicle
What is
B. Gas Price
400
Which is the correct import statement for the ArrayList class?
A. import java.awt.ArrayList
B. import java.io.ArrayList
C. import java.util.ArrayList
D. import java.ArrayList
E. import util.io.ArrayList
What is
C. import java.util.ArrayList
400
What is output?
What is
MOUSE
SPEAKERS
SCANNER
SCREEN
400
The ______ methods are used to change variables in classes, while the ______ methods are used to return the data.
A. mutator, accessor
B. accessor, mutator
What is
A. mutator, accessor
400
What is true about private constructors?
A. Private constructor ensures only one instance of a class exist at any point of time
B. Private constructor ensures multiple instances of a class exist at any point of time
C. Private constructor eases the instantiation of a class
D. Private constructor allows creating objects in other classes
What is
A. Private constructor ensures only one instance of a class exist at any point of time
400
You are writing a class for a chain of businesses with the same hours. Which of the following would you want to make static?
A. A boolean to determine if the stores are opened or closed.
B. A double to hold store revenue.
C. A String to hold store phone number.
D. A String to hold business location.
What is
A. A boolean to determine if the stores are opened or closed.
500
What is printed as a result of executing "System.out.println(sequence(5));"
What is
[5, 7, 9, 11, 13]
500
The method timesContained is intended to return the number of times the string str is contained in the ArrayList words. What code can replace /* missing expression */ so that timesContained works as intended?
What is
500
Suppose nums = {0, 3, 1, 1, 1, 6, 6}. What is returned by the call repeatHelper(3)?
What is
3
500
The line, stack.add(new Box()); calls the ______ of Box.
A. equals method
B. static method
C. toString
D. default constructor
E. mutator
What is
D. default constructor
500
Which of these cannot be declared static?
A. class
B. object
C. variable
D. method
What is
B. object