Midterm T/F

Question 1

unsigned int is a value type in Java for representing unsigned integer numeric values

Answer 1

False

Java does not support unsigned data types

Question 2

String is a built-in value type in Java

Answer 2

False
String is a built-in class in java

Question 3

A class name usually starts with a capital letter.

Answer 3

True

Question 4

switch is a valid variable name

Answer 4

False

switch is a statement in java.

Question 5

An instance of a class is always a reference type in Java

Answer 5

True

An object is a reference type.

Question 6

An object reference is not a valid expression

Answer 6

False.

The reference of an object is valid

Question 7

A variable can be assigned the result of any expression

Answer 7

False

Question 8

An if statement is a type of loop

Answer 8

False.

An if statement does not loop

Question 9

A continue statement within the body of a loop exits the loop

Answer 9

False
continue (keyword) is used in loops
for: causes control to immediately jump to the update statement
while: control immediately jumps to the boolean expression.

Question 10

A continue statement within the body of a loop exits the loop

Answer 10

False
continue (keyword) is used in loops
for: causes control to immediately jump to the update statement
while: control immediately jumps to the boolean expression.

Question 11

A local variable declared within a loop is not available outside of the body of the loop.

Answer 11

True.

No.

Question 12

Several case statements within a switch statement may be associated with the same block of statements to be executed.

Answer 12

True.

Yes.

Question 13

A method must return a value that can be used in an expression

Answer 13

False

A method can be void

Question 14

To invoke (i.e., call) a method, you must provide a value for each parameter declared in the method’s signature.

Answer 14

True

Yes.

Question 15

Invoking a class method - a static method - requires a reference to a particular instance (i.e., object) of the class.

Answer 15

False

A static method can be invoked without the need for creating an instance of a class.

Question 16

When a method is called from within another method, the code within method A can access local variable within method B at the point where the call to method A was made.

Answer 16

False

No.

Question 17

The length of an array in Java cannot be changed after the array is created

Answer 17

True

You can not modify the length of an array after it is created.

Question 18

A specific array in java cannot be changed after the array is created.

Answer 18

True

Yes.

Question 19

A specific array can hold values of any type.

Answer 19

False

No.

Question 20

The individual characters of a String object can be changed

Answer 20

False

Question 21

The principle of encapsulation encourages object fields to be marked private

Answer 21

True

Question 22

Every method of a class should be included in at least one of the interfaces that the class implements.

Answer 22

False

Question 23

Overloading a method is an example of the principle of encapsulation

Answer 23

False

Question 24

Setters should never be provided for an immutable object

Answer 24

True

Question 25

To adhere to the principle of encapsulation, a public method should not make use of (i.e., call) a private method declared in the same class.

Answer 25

False

Question 26

It is possible to create an instance of a class that does not explicitly define a constructor

Answer 26

True

Question 27

Multiple constructors that accept different types and number of parameters is an example of polymorphism.

Answer 27

True Polymorphism= many forms General principle of providing access to an abstraction or method in many forms. Ex: constructor overloading, method overloading, subinterfaces

Question 28

A constructor that chains to another constructor must do so as the first statement of the constructor body

Answer 28

True. | Ex: super();

Question 29

Two different versions of the same method can be declared to accept the same number and type of parameters as long as the parameters have been given different names.

Answer 29

False

Question 30

All of the methods declared in an interface must be implemented as public methods

Answer 30

True

Question 31

An interface may only extend a single parent interface

Answer 31

``` False A class can only extend one parent class. But an interface can extend more than one parent interface. ```

Question 32

Every class must implement at least one interface

Answer 32

False | Ex: main

Question 33

An interface may declare several different versions (overload) the same method name

Answer 33

True

Question 34

The name of an interface is a valid type name that can be used as the type of a variable

Answer 34

True

Question 35

A class that implements an extended interface must implement all of the methods declared in the parent interface of the extended interface.

Answer 35

True

Question 36

A subclass that extends a parent class automatically implements any interfaces that the parent class implements

Answer 36

True

Question 37

An instance field marked as private can be directly accessed by outside of that class

Answer 37

False

Question 38

An instance of a subclass can always be used wherever a reference to an object with the parent class type is required

Answer 38

True

Question 39

A subclass can extend from more than one parent class.

Answer 39

False

Question 40

The scope of a local variable in a method is limited to the statement block where it is declared

Answer 40

True

Question 41

A constructor may throw an exception

Answer 41

True

Question 42

One constructor can call another constructor in the same class using the super keyword as if it were a method name.

Answer 42

False | We use super for the constructor of that specific class's parent class.

Question 43

A setter method conforming to the Java Beans convention should return the new value of the property.

Answer 43

False

Question 44

An interface definition can includde private or protected methods

Answer 44

False

Question 45

An iterator provides a way to access elements of an aggregate object sequentially by exposing its underlying representation

Answer 45

False

Question 46

Traversing an array using an integer index incremented as a for-loop variable is an example of the iterator design pattern.

Answer 46

False

Question 47

An expression can always be used where ever a value is required

Answer 47

True

Question 48

The state of an object is defined by the current values of all of its instance fields.

Answer 48

True

Question 49

An iterator assumes that the underlying collection is not changed or modified while the traversal occurs

Answer 49

True

Question 50

Class names, interface names, and enumeration names can all serve as the data type of a variable

Answer 50

True | Think: a4 sushi

Question 51

In an instance method, the this keyword always provides a reference to the specific instance used to invoke (call) the method.

Answer 51

True

Question 52

A method's signature is defined by its return type and the sequence of types associated with its parameters

Answer 52

True

Question 53

Polymorphic methods with the same name may have different return types

Answer 53

True

Question 54

Polymorphic methods with the same name must have distinct method signatures

Answer 54

True

Question 55

Enumerations provide a type-safe mechanism for an object property that can be set to one of a distinct set of values

Answer 55

True | Basically the definition

Question 56

Different classes that implement the same set of interfaces may also have different and additional behavior not declared by those interfaces

Answer 56

True

Question 57

Two object references that have the same value always refer to the same object.

Answer 57

True

Question 58

A class that implements a subinterface must provide implementations for methods declared by the subinterface as well as any parent interfaces that subinterface

Answer 58

True

Question 59

A subclass has direct access to private and protected fields and methods in its parent class

Answer 59

False

Question 60

The catch or specify policy applies to all subclasses of Exception

Answer 60

False

Question 61

In general, you should catch an exception at the earliest point at which the exception can be detected.

Answer 61

False

Question 62

*All overriding methods in Java are virtual

Answer 62

True

Question 63

If a catch block is provided for the Exception parent class. it should appear first before any other catch blocks.

Answer 63

False

Question 64

An abstract class can not be instantiated directly

Answer 64

True

Question 65

The return type of a getter method following JavaBeans conventions may bee void

Answer 65

False