True or false? An object of a class that implements an interface may be thought of as an object of that interface type.
Answer: True
True or false? If a superclass declares an abstract method, a subclass must implement that method.
True or false? If a superclass declares an abstract method, a subclass must implement that method.
Answer: False
True or false? Invoking a subclass-only method through a subclass variable is not allowed.
True or false? Invoking a subclass-only method through a subclass variable is not allowed.
Answer: False
True or false? All methods in an abstract class must be declared as abstract methods.
True or false? All methods in an abstract class must be declared as abstract methods.
Answer: False
Casting a reference stored in a superclass variable to a subclass type is called __________.
Casting a reference stored in a superclass variable to a subclass type is called __________.
Answer: Downcasting
Methods that are not interface methods and that do not provide implementations must be declared using keyword __________.
Methods that are not interface methods and that do not provide implementations must be declared using keyword __________.
Answer: Abstract
_________ involves using a superclass variable to invoke methods on superclass and subclass objects, enabling you to "program in the general."
_________ involves using a superclass variable to invoke methods on superclass and subclass objects, enabling you to "program in the general."
Answer: Polymorphism
Classes from which objects can be instantiated are called __________ classes.
Classes from which objects can be instantiated are called __________ classes.
Answer: Concrete
If a class contains at least one abstract method, it's a(n) __________ class.
If a class contains at least one abstract method, it's a(n) __________ class.
Answer: Abstract
True or false? A Car class has an is-a relationship with the SteeringWheel and Brakes classes.
True or false? A Car class has an is-a relationship with the SteeringWheel and Brakes classes.
Answer: False
True or false? A has-a relationship is implemented via inheritance.
True or false? A has-a relationship is implemented via inheritance.
Answer: False
True or false? Superclass constructors are not inherited by subclasses.
True or false? Superclass constructors are not inherited by subclasses.
Answer: True
Subclass constructors can call superclass constructors via the __________ keyword.
Subclass constructors can call superclass constructors via the __________ keyword.
Answer: Super
When an object of a subclass is instantiated, a superclass __________ is called implicitly or explicitly.
When an object of a subclass is instantiated, a superclass __________ is called implicitly or explicitly.
Answer: Constructor
A superclass's __________ members are accessible anywhere that the program has a reference to an object of that superclass or to an object of one of its subclasses.
A superclass's __________ members are accessible anywhere that the program has a reference to an object of that superclass or to an object of one of its subclasses.
Answer: Public
In single inheritance, a class exists in a(n) __________ relationship with its subclasses
In single inheritance, a class exists in a(n) __________ relationship with its subclasses
Answer: Hierarchical
In a(n) __________ relationship, a class object has references to objects of other classes as members.
In a(n) __________ relationship, a class object has references to objects of other classes as members.
Answer: Has-a
In a(n) __________ relationship, an object of a subclass can also be treated as an object of its superclass.
In a(n) __________ relationship, an object of a subclass can also be treated as an object of its superclass.
Answer: Is-a
A superclass's __________ members can be accessed in the superclass declaration and in subclass declarations.
A superclass's __________ members can be accessed in the superclass declaration and in subclass declarations.
Answer: Public and protected
__________ is a form of software reusability in which new classes acquire the members of existing classes and embellish those classes with new capabilities.
__________ is a form of software reusability in which new classes acquire the members of existing classes and embellish those classes with new capabilities.
Answer: Inheritance
True or false? When a subclass redefines a superclass method by using the same signature, the subclass is said to overload that superclass method.
True or false? When a subclass redefines a superclass method by using the same signature, the subclass is said to overload that superclass method.
Answer: False
True or false? A Car class has an is-a relationship with the SteeringWheel and Brakes classes.
True or false? A Car class has an is-a relationship with the SteeringWheel and Brakes classes.
Answer: False
True or false? A has-a relationship is implemented via inheritance.
True or false? A has-a relationship is implemented via inheritance.
Answer: False
True or false? Superclass constructors are not inherited by subclasses.
True or false? Superclass constructors are not inherited by subclasses.
Answer: True
Subclass constructors can call superclass constructors via the __________ keyword.
Subclass constructors can call superclass constructors via the __________ keyword.
Answer: Super
When an object of a subclass is instantiated, a superclass __________ is called implicitly or explicitly.
When an object of a subclass is instantiated, a superclass __________ is called implicitly or explicitly.
Answer: Constructor
A superclass's __________ members are accessible anywhere that the program has a reference to an object of that superclass or to an object of one of its subclasses.
A superclass's __________ members are accessible anywhere that the program has a reference to an object of that superclass or to an object of one of its subclasses.
Answer: Public
In single inheritance, a class exists in a(n) __________ relationship with its subclasses
In single inheritance, a class exists in a(n) __________ relationship with its subclasses
Answer: Hierarchical
In a(n) __________ relationship, a class object has references to objects of other classes as members.
In a(n) __________ relationship, a class object has references to objects of other classes as members.
Answer: Has-a
In a(n) __________ relationship, an object of a subclass can also be treated as an object of its superclass.
In a(n) __________ relationship, an object of a subclass can also be treated as an object of its superclass.
Answer: Is-a
A superclass's __________ members can be accessed in the superclass declaration and in subclass declarations.
A superclass's __________ members can be accessed in the superclass declaration and in subclass declarations.
Answer: Public and protected
__________ is a form of software reusability in which new classes acquire the members of existing classes and embellish those classes with new capabilities.
__________ is a form of software reusability in which new classes acquire the members of existing classes and embellish those classes with new capabilities.
Answer: Inheritance
Use the __________ statement to indicate that a problem has occurred.
Use the __________ statement to indicate that a problem has occurred.
Answer: Throw
Use class __________ to perform precise monetary calculations.
Use class __________ to perform precise monetary calculations.
Answer: BigDecimal
Set methods are commonly called __________ because they typically change a value.
Set methods are commonly called __________ because they typically change a value.
Answer: Mutator methods
A(n) __________ declaration imports only the classes that the program uses from a particular package.
A(n) __________ declaration imports only the classes that the program uses from a particular package.
Answer: Type-import-on-demand
Keyword __________ specifies that a variable is not modifiable after initialization in a declaration or constructor.
Keyword __________ specifies that a variable is not modifiable after initialization in a declaration or constructor.
Answer: Final
The __________ states that code should be granted only the amount of privilege and access that it needs to accomplish its designated task.
The __________ states that code should be granted only the amount of privilege and access that it needs to accomplish its designated task.
Answer: Principle of least privilege
A(n) __________ declaration imports one static member.
A(n) __________ declaration imports one static member.
Answer: Single static import
A(n) __________ variable represents classwide information that's shared by all the objects of the class.
A(n) __________ variable represents classwide information that's shared by all the objects of the class.
Answer: Static
A(n) __________ declaration contains a comma-separated list of constants.
A(n) __________ declaration contains a comma-separated list of constants.
Answer: Enum
Composition is sometimes referred to as a(n) __________ relationship.
Composition is sometimes referred to as a(n) __________ relationship.
Answer: Has-a
For every enum, the compiler generates a static method called __________ that returns an array of the enum's constants in the order in which they were declared.
For every enum, the compiler generates a static method called __________ that returns an array of the enum's constants in the order in which they were declared.
Answer: Values
A(n) __________ method tests whether a condition is true or false.
A(n) __________ method tests whether a condition is true or false.
Answer: Predicate
Get methods are commonly called __________ or __________.
Get methods are commonly called __________ or __________.
Answer: Accessor methods, query methods
An object's __________ method is called implicitly when an object appears in code where a String is needed.
An object's __________ method is called implicitly when an object appears in code where a String is needed.
Answer: toString
If a class declares constructors, the compiler will not create a(n) __________.
If a class declares constructors, the compiler will not create a(n) __________.
Answer: Default constructor
A(n) __________ declaration specifies one class to import.
A(n) __________ declaration specifies one class to import.
Answer: Single-type import
The public methods of a class are also known as the class's __________ or __________.
The public methods of a class are also known as the class's __________ or __________.
Answer: Public services, public interface
If a method contains a local variable with the same name as one of its class's fields, the local variable __________ the field in that method's scope.
If a method contains a local variable with the same name as one of its class's fields, the local variable __________ the field in that method's scope.
Answer: Shadows
String class static method __________ is similar to method System.out.printf, but returns a formatted String rather than displaying a String in a command window.
String class static method __________ is similar to method System.out.printf, but returns a formatted String rather than displaying a String in a command window.
Answer: Format
A(n) __________ imports all static members of a class.
A(n) __________ imports all static members of a class.
Answer: Static import on demand
Command-line arguments are stored in __________.
Command-line arguments are stored in __________.
Answer: An array of Strings, called args by convention
Use the enhanced for statement __________ to walk through double array numbers.
Use the enhanced for statement __________ to walk through double array numbers.
Answer: For (double d : numbers)
True or false? Command-line arguments are separated by commas.
True or false? Command-line arguments are separated by commas.
Answer: False
True or false? An individual array element that's passed to a method and modified in that method will contain the modified value when the called method completes execution.
True or false? An individual array element that's passed to a method and modified in that method will contain the modified value when the called method completes execution.
Answer: False? True?
True or false? An array index should normally be type float.
True or false? An array index should normally be type float.
Answer: False
True or false? An array can store many different types of values.
True or false? An array can store many different types of values.
Answer: False
A(n) __________ in the parameter list of a method indicates that the method can receive a variable number of arguments.
A(n) __________ in the parameter list of a method indicates that the method can receive a variable number of arguments.
Answer: Ellipsis
Given the command java MyClass test, the first command-line argument is __________.
Given the command java MyClass test, the first command-line argument is __________.
Answer: Test
Use the expression __________ to receive the total number of arguments in a command line. Assume that command-line arguments are stored in String[] args.
Use the expression __________ to receive the total number of arguments in a command line. Assume that command-line arguments are stored in String[] args.
Answer: Args.length
An array that uses two indices is referred to as a(n) __________ array.
An array that uses two indices is referred to as a(n) __________ array.
Answer: Two-dimensional
The number used to refer to a particular array element is called the element's __________.
The number used to refer to a particular array element is called the element's __________.
Answer: Index
The __________ allows you to iterate through an array's elements without using a counter.
The __________ allows you to iterate through an array's elements without using a counter.
Answer: Enhanced for statement
An array is a group of __________ (called elements or components) containing values that all have the same __________.
An array is a group of __________ (called elements or components) containing values that all have the same __________.
Answer: Variables, type
Lists and tables of values can be stored in __________ and __________.
Lists and tables of values can be stored in __________ and __________.
Answer: Arrays, collections
It's possible to have several methods with the same name that each operate on different types or numbers of arguments. This feature is called method __________.
It's possible to have several methods with the same name that each operate on different types or numbers of arguments. This feature is called method __________.
Answer: Overloading
The __________ of a declaration is the portion of a program that can refer to the entity in the declaration by name.
The __________ of a declaration is the portion of a program that can refer to the entity in the declaration by name.
Answer: Scope
If there are more method calls than can be stored on the method-call stack, an error known as a(n) __________ occurs.
If there are more method calls than can be stored on the method-call stack, an error known as a(n) __________ occurs.
Answer: Stack overflow
The method-call stack contains the memory for local variables on each invocation of a method during a program's execution. This data, stored as a portion of the method-call stack, is known as the __________ or __________ of the method call.
The method-call stack contains the memory for local variables on each invocation of a method during a program's execution. This data, stored as a portion of the method-call stack, is known as the __________ or __________ of the method call.
Answer: Stack frame, activation record
An object of class __________ produces truly random numbers.
An object of class __________ produces truly random numbers.
Answer: SecureRandom
The three ways to return control from a called method to a caller are __________, __________, and __________.
The three ways to return control from a called method to a caller are __________, __________, and __________.
Answer: Return, return expression, closing brace
Stacks are known as __________ data structures; the last item pushed (inserted) onto the stack is the first item popped (removed) from the stack.
Stacks are known as __________ data structures; the last item pushed (inserted) onto the stack is the first item popped (removed) from the stack.
Answer: LIFO
Data can be added or removed only from the __________ of a stack.
Data can be added or removed only from the __________ of a stack.
Answer: Top
The keyword __________ indicates that a method does not return a value.
The keyword __________ indicates that a method does not return a value.
Answer: Void
The __________ statement in a called method can be used to pass the value of an expression back to the calling method
The __________ statement in a called method can be used to pass the value of an expression back to the calling method
Answer: Return
A variable known only within the method in which it's declared is called a(n) __________.
A variable known only within the method in which it's declared is called a(n) __________.
Answer: Local variable
A method is invoked with a(n) __________.
A method is invoked with a(n) __________.
Answer: Method call
True or false? Listing cases consecutively with no statements between them enables the cases to perform the same set of statements.
True or false? Listing cases consecutively with no statements between them enables the cases to perform the same set of statements.
Answer: True
True or false? To test for a range of values in a switch statement, use a hyphen between the start and end values of the range in a case label.
True or false? To test for a range of values in a switch statement, use a hyphen between the start and end values of the range in a case label.
Answer: False
True or false? The comma (,) formatting flag in a format specifier indicates that a value should be output with a thousands separator.
True or false? The comma (,) formatting flag in a format specifier indicates that a value should be output with a thousands separator.
Answer: True
True or false? An expression containing the || operator is true if either or both of its operands are true.
True or false? An expression containing the || operator is true if either or both of its operands are true.
Answer: True
True or false? The expression ((x > y) && (a < b)) is true if either x > y is true or a < b is true.
True or false? The expression ((x > y) && (a < b)) is true if either x > y is true or a < b is true.
Answer: False
True or false? The break statement is required in the last case of a switch selection statement.
True or false? The break statement is required in the last case of a switch selection statement.
Answer: False
True or false? The default case is required in the switch selection statement.
True or false? The default case is required in the switch selection statement.
Answer: False
Methods that perform common tasks and do not require objects are called __________ methods.
Methods that perform common tasks and do not require objects are called __________ methods.
Answer: Static
If the loop-continuation condition in a for header is initially __________, the program does not execute the for statement's body.
If the loop-continuation condition in a for header is initially __________, the program does not execute the for statement's body.
Answer: False
The __________ operator can be used to ensure that two conditions are both true before choosing a certain path of execution.
The __________ operator can be used to ensure that two conditions are both true before choosing a certain path of execution.
Answer: &&
The __________ statement, when executed in a repetition statement, skips the remaining statements in the loop body and proceeds with the next iteration of the loop.
The __________ statement, when executed in a repetition statement, skips the remaining statements in the loop body and proceeds with the next iteration of the loop.
Answer: Continue
The __________ statement selects among multiple actions based on the possible values of an integer variable or expression, or a String.
The __________ statement selects among multiple actions based on the possible values of an integer variable or expression, or a String.
Answer: Switch
The do...while statement tests the loop condition __________ executing the loop's body; therefore, the body always executes at least once.
The do...while statement tests the loop condition __________ executing the loop's body; therefore, the body always executes at least once.
Answer: After
Typically, __________ statements are used for counter-controlled repetition and __________ statements for sentinel-controlled repetition.
Typically, __________ statements are used for counter-controlled repetition and __________ statements for sentinel-controlled repetition.
Answer: For, while
True or false? Pseudocode helps you think out a program before attempting to write it in a programming language.
True or false? Pseudocode helps you think out a program before attempting to write it in a programming language.
Answer: True
True or false? Instance variables of type boolean are given the value true by default.
True or false? Instance variables of type boolean are given the value true by default.
Answer: False
True or false? The unary cast operator (double) creates a temporary integer copy of its operand.
True or false? The unary cast operator (double) creates a temporary integer copy of its operand.
Answer: False
True or false? Specifying the order in which statements execute in a program is called program control.
True or false? Specifying the order in which statements execute in a program is called program control.
Answer: True
True or false? The primitive types (boolean, char, byte, short, int, long, float, and double), are portable across only Windows platforms.
True or false? The primitive types (boolean, char, byte, short, int, long, float, and double), are portable across only Windows platforms.
Answer: False
True or false? Java provides the arithmetic compound assignment operators +=, -+, *=, /=, and %= for abbreviating assignment expressions.
True or false? Java provides the arithmetic compound assignment operators +=, -+, *=, /=, and %= for abbreviating assignment expressions.
Answer: True
True or false? A nested control statement appears in the body of another control statement.
True or false? A nested control statement appears in the body of another control statement.
Answer: True
True or false? A selection statement specifies that an action is to be repeated while some condition remains true.
True or false? A selection statement specifies that an action is to be repeated while some condition remains true.
Answer: False
True or false? A set of statements contained within a pair of parentheses is called a block.
True or false? A set of statements contained within a pair of parentheses is called a block.
Answer: False
True or false? An algorithm is a procedure for solving a problem in terms of the actions to execute and the order in which they execute.
True or false? An algorithm is a procedure for solving a problem in terms of the actions to execute and the order in which they execute.
Answer: True
If the increment operator is __________ to a variable, first the variable is incremented by 1, then its new value is used in the expression.
If the increment operator is __________ to a variable, first the variable is incremented by 1, then its new value is used in the expression.
Answer: Prefixed
Java is a(n) __________ language; it requires all variables to have a type.
Java is a(n) __________ language; it requires all variables to have a type.
Answer: Strongly typed
Instance variables of types char, byte, short, int, long, float, and double are all given the value __________ by default.
Instance variables of types char, byte, short, int, long, float, and double are all given the value __________ by default.
Answer: 0
The __________ structure is built into Java; by default, statements execute in the order they appear.
The __________ structure is built into Java; by default, statements execute in the order they appear.
Answer: Sequence
When it's not known in advance how many times a set of statements will be repeated a(n) __________ value can be used to terminate the repetition.
When it's not known in advance how many times a set of statements will be repeated a(n) __________ value can be used to terminate the repetition.
Answer: Sentinel, signal, flag, or dummy
Repeating a set of instructions a specific number of times is called __________ repetition.
Repeating a set of instructions a specific number of times is called __________ repetition.
Answer: Counter-controlled (or definite)
The __________ statement is used to execute one action when a condition is true and another when that condition is false.
The __________ statement is used to execute one action when a condition is true and another when that condition is false.
Answer: If...else
All programs can be written in terms of three types of control structures: __________, __________, and __________.
All programs can be written in terms of three types of control structures: __________, __________, and __________.
Answer: Sequence, selection, repetition
Subscribe to:
Posts (Atom)