Cse 421 Midterm

Front 1

8 Different primitive types in java

Back 1

boolean, int, float, long, double, byte, char, short

Front 2

When are primitive values initialized?

Back 2

When declared globally but not locally

Front 3

Good Practice - When writing floats or longs in the program it is good to write ____

Back 3

L after longs and f after floats

Front 4

Hierarchy of primitive types

Back 4

Double
Float
Long
Int
Short - Char
Byte

Boolean

Front 5

Widening

Back 5

Casting from a type lower on the hierarchy to a type higher than. (Implicit but can be type casted)

Front 6

Narrowing

Back 6

Casting from a type higher on the hierarchy to a type lower than.
(Requires an explicit cast and can cause a loss of information)

Front 7

A variable is the name of a ______ that holds a ________

Back 7

Memory location, Value

Front 8

Declaration ______ the variable name to a _________

Back 8

binds, memory location

Front 9

assignment _________ contents of memory

Back 9

copies

Front 10

Parameters are ________

Back 10

copies

Front 11

Examples of reference types

Back 11

User created classes, arrays, Integer, Long, Double, Java provided classes

Front 12

For reference types, the _______ in the memory location is a _________ to the actual object

Back 12

value, pointer

Front 13

Assignment of a reference copies the __________

Back 13

pointer

Front 14

Parameter passing for a reference copies the ________

Back 14

pointer

Front 15

IDE

Back 15

integrated development environment

Front 16

State of an object

Back 16

Data the object holds

Front 17

Behavior of an object

Back 17

how state changes

Front 18

Each object is an _________ of a class

Back 18

instance

Front 19

Fields

Back 19

data that determine the state of the object, i.e. variables

Front 20

Methods

Back 20

procedures that access/modify the state of the object

Front 21

Private members

Back 21

can be accessed only by instances of the same class

Front 22

Public members

Back 22

can be accessed by any object

Front 23

Static Members

Back 23

Allow all instances of a class to access one shared piece of data. However, can not access instance members.

Front 24

How are constants declared

Back 24

with the final keyword

Front 25

What is a package

Back 25

A grouping of classes

Front 26

What does a package provide

Back 26

1.) Logical structuring, related classes are bundled
2.) encapsulation - another level of class control
3.) Distinct namespace

Front 27

What is the naming convention for a package

Back 27

Reverse of companies domain name

www.cse.ohio-state.edu

goes to

edu.ohio-state.cse

Front 28

What is the purpose of a static initialization block

Back 28

To initialize a static variable. However, it can only modify static variables.

Front 29

What is an interface

Back 29

A set of requirements that describes what a class should do and describe how they should do it

Front 30

Requirements/Constraints of an interface

Back 30

1.) Must be declared public interface
2.) Methods have no bodies
3.) No constructors provided
4.) Can only have static variables

Front 31

Interfaces should provide

Back 31

1.) Method signatures
2.) Mathematical Model
3.) Constraints (Invariants)
4.) Method specifications

Front 32

Declared Type

Back 32

Object whose type is declared at compile time

Front 33

Dynamic Type

Back 33

Object whose type is declared at run time

Front 34

What does coding to the interface mean

Back 34

All declared types are types of the interface

Front 35

Classes should provide

Back 35

1.) Concrete representation of the object

Front 36

Accessor Method

Back 36

A method that reads, but never changes, the state of an object.

ex. getter methods

Front 37

Mutator Method

Back 37

A method that modifies the state of an object

ex. setter methods

Front 38

Steps to take when making a defensive copy of a constructor argument

Back 38

1.) copy the arguments
2.) Check the validity of the arguments

Front 39

Immutability

Back 39

An object whose abstract value can never be changed, no mutator methods

Front 40

Steps to write an immutable class

Back 40

1.) Write an immutable interface
2.) Make all fields private
3.) Ensure exclusive access to any mutable objects referred to by fields

Front 41

When declaring an immutable class declare it to be ________

Back 41

final

Front 42

Review JUNIT

Back 42

DO IT

Front 43

T is called what

Back 43

Naked Type

Front 44

Interface Box<T>

What is Box called

Back 44

raw type

Front 45

Comparable is used for what and what are the 3 requirements for a good comparable method

Back 45

Compare the natural ordering of items in a class

1.) Antisymmetric
2.) Transitive
3.) Reflexive

Front 46

What would comparable return for the following:

x = 5
y = 10
z = 10

1.) x < y
2.) y > x
3.) y = x

Back 46

1.) -1
2.) 1
3.) 0

Front 47

What does extending an interface mean

Back 47

An interface can extend another and receives all methods declared in interfaces above

Front 48

Subinterfaces are ______ types than superinterfaces

Back 48

smaller

Front 49

Behavior Subtype

Back 49

A class 'x' is a behavioral subtype of a class 'y' if 'x' can do everything 'y' can and potentially more

Front 50

3 requirements for behavioral subtyping

Back 50

1.) invariant is stronger
2.) methods require less
3.) methods ensure more

Front 51

What kind of inheritance does java have

Back 51

Single inheritance

Front 52

What does a subclass inherent from its superclass

Back 52

all members that aren't private and does not get constructors

Front 53

what does the final keyword on a class do

Back 53

prevent another class from extending it

Front 54

Protected

Back 54

signifies that the method or variable can only be accessed by elements residing in its class, subclasses, or classes in the same package.

Front 55

Abstract classes are different from interfaces how

Back 55

1.) Allows for constructors
2.) Static methods
3.) Fields
4.) Visibilities
5.) Implementations

Front 56

Static methods in inherited classes

Back 56

Static methods are not inherited