Computer Programming Test #2
Which symbol indicates that a member is public in a UML diagram? a) # b) + c) * d) -
+
Which symbol indicates that a member is private a UML diagram? a) * b) + c) - d) #
-
A method that gets a value from a class's field but does not change it is known as a mutator method. a) True b) False
False
The public access specifier for a field indicates that the field may not be accessed by statements outside the class. a) True b) False
False
The term "default constructor" is applied to the first constructor written by the author of the class. a) True b) False
False
When a local variable in an instance method has the same name as an instance field, the instance field hides the local variable. a) True b) False
False
For the following code, which statement is not true? public class Circle { private double radius;public double x;private double y; } a) The radius field is not available to code written outside the Circle class. b) The x field is available to code that is written outside the Circle class. c) The radius, x, and y fields are members of the Circle class. d) The y field is available to code written outside the Circle class.
The y field is available to code written outside the Circle class.
For the following code, which statement is not true? public class Sphere { private double radius;public double x;private double y;private double z; } a) The x field is available to code that is written outside the Sphere class. b) The z field is available to code written outside the Sphere class. c) The radius, x, y, and z fields are members of the Sphere class. d) The radius field is not available to code written outside the Sphere class.
The z field is available to code written outside the Sphere class.
"Shadowing" is the term used to describe how the field name is hidden by the name of a local or parameter variable. a) True b) False
True
A constructor is a method that is automatically called when an object is created. a) True b) False
True
A method that stores a value in a class's field or in some other way changes the value of a field is known as a mutator method. a) True b) False
True
An access specifier indicates how a class may be accessed. a) True b) False
True
Each instance of a class has its own set of instance fields. a) True b) False
True
The java.lang package is automatically imported into all Java programs. a) True b) False
True
The term "no-arg constructor" is applied to any constructor that does not accept arguments. a) True b) False
True
What does the following UML diagram entry mean? + setHeight(h : double) : void a) a public field called Height that is a double data type b) a public method with a parameter of data type double that does not return a value c) a private field called setHeight that is a double data type d) a private method with no parameters that returns a double data type
a public method with a parameter of data type double that does not return a value
What is the following statement an example of? import java.util.*; a) an explicit import statement b) a wildcard import statement c) a conditional import statement d) an unconditional import statement
a wildcard import statement
What is the following statement an example of? import java.util.Scanner; a) an explicit import statement b) a wildcard import statement c) a conditional import statement d) an unconditional import statement
an explicit import statement
Which of the following is not involved in identifying the classes to be used when developing an object-oriented application? a) Refine the list of nouns to include only those relevant to the problem. b) Write the code. c) Describe the problem domain. d) Identify all the nouns.
b) Write the code.
If you do not provide initialization values for a class's numeric fields, they will a) cause a compiler error b) cause a runtime error c) be automatically initialized to 0 d) contain an unknown value
be automatically initialized to 0
A class's responsibilities include a) the things a class is responsible for doing b) neither of these c) both of these d) the things a class is responsible for knowing
both of these
After the header, the body of the method appears inside a set of a) parentheses, ( ) b) brackets, [ ] c) braces, { } d) double quotes, " "
braces, {}
One or more objects may be created from a(n) a) method b) instance c) field d) class
class
The key word new a) creates a new variable in memory b) creates a new Java byte code file c)creates a new class d) creates an object in memory
creates an object in memory
It is common practice in object-oriented programming to make all of a class's a) methods private b) fields public c) fields and methods public d) fields private
fields private
A constructor a) always accepts two arguments b) has the return type of void c) has the same name as the class d) always has a private access specifier
has the same name as the class
Another term for an object of a class is a(n) a) access specifier b) member c) method d) instance
instance
When an object is created, the attributes associated with the object are called a) class instances b) fixed attributes c) instance methods d) instance fields
instance fields
Methods that operate on an object's fields are called a) instance methods b) private methods c) instance variables d) public methods
instance methods
A method a) may have zero or more parameters b) must have at least two parameter variables c) may not have only one parameter variable d) never has parameter variables
may have zero or more parameters
Class objects normally have __________ that perform useful operations on their data, but primitive variables do not. a) methods b) instances c) relationships d) fields
methods
UML diagrams do not contain a) fields b) object names c) methods d) class names
object names
Using the blueprint/house analogy, you can think of a class as a blueprint that describes a house and __________ as instances of the house built from the blueprint. a) methods b) objects c) attributes d) fields
objects
A group of related classes is called a(n) a) attachment b) archive c) collections d) package
package
A constructor is a method that a) removes the object from memory b) returns an object of the class c) never receives any arguments d) performs initialization or setup operations
performs initialization or setup operations
When the value of an item is dependent on other data, and that item is not updated when the other data is changed, what has the value become? a) stale b) moldy c) asynchronous d) bitter
stale
The scope of a local variable is a) the method in which it is defined b) inside the parentheses of a method header c) the entire class d) inside the class but not inside any method
the method in which it is defined
When an argument is passed by value a) the parameter variable holds the address of the argument b) the parameter variable holds a copy of the value passed to it c) changes can be made to the argument variable d) the parameter variable cannot be changed
the parameter variable holds the address of the argument
To indicate the data type of a variable in a UML diagram you specify a) the data type followed by the variable name b) the class name followed by the variable name followed by the data type c) the variable name followed by a colon and the data type d) the variable name followed by the data type
the variable name followed by a colon and the data type
Data hiding (which means that critical data stored inside the object is protected from code outside the object) is accomplished in Java by a) using the private access specifier on the class fields b) using the private access specifier on the class definition c) using the private access specifier on the class methods d) using the public access specifier on the class methods
using the private access specifier on the class fields
