COP2253 Zybooks Chapter Seven

Question 1

object

Answer 1

a grouping of data (variables) and operations that can be performed on that data (methods)

Question 2

abstraction (or information hiding or excapsulation)

Answer 2

means to have a user interact with an item at a high-level, with lower-level internal details hidden from the user

Question 3

ADT

Answer 3

abstract data type

Question 4

class

Answer 4

defines a new type that can group data and methods to form an object

Question 5

public member methods

Answer 5

indicate all operations a class user can perform on the object

Question 6

creating an object consists of two steps:

Answer 6

declaring a reference variable of the class type, and assigning the variable with an explicitly allocated instance of the class type

Question 7

new operator

Answer 7

explicitly allocates an object of he specified class type

Question 8

member access operator

Answer 8

”.” used to invoke a method on an object

Question 9

private fields

Answer 9

variables that member methods can access but class users cannot

Question 10

class members

Answer 10

collectively, a class’ fields and methods

Question 11

method definition

Answer 11

provides an access modifier, return type, name, arguments, and the method’s statements

Question 12

mutator (setter)

Answer 12

method may modify a class’ fields

Question 13

accessor (getter)

Answer 13

method accesses but may not modify a class’ fields

Question 14

constructor

Answer 14

a special class member that is called when an object of that class type is created and which can be used to initialize all fields (has the same name as the class and has NO return type)

Question 15

default constructor

Answer 15

a constructor called without any arguments

Question 16

border cases

Answer 16

unusual or extreme test case values like 0, negative numbers, or large numbers

Question 17

regression testing

Answer 17

to retest an item like a class anytime that item is changed (if previously-passed test cases fail, the item has regressed)

Question 18

reference

Answer 18

a variable type that refers to an object

Question 19

implicit parameter

Answer 19

the object reference before the method name

Question 20

this.

Answer 20

keyword used to access an implicitly passed object reference

Question 21

primitive type

Answer 21

variable directly stores the data for that variable type

Question 22

reference type

Answer 22

variable can refer to an instance of a class (object)

Question 23

wrapper classes

Answer 23

built-in reference types that augment the primitive types

Question 24

autoboxing

Answer 24

the automatic conversion of primitive types to the corresponding wrapper classes

Question 25

unboxing

Answer 25

the automatic conversion of wrapper class objects to the corresponding primitive types

Question 26

static field (or class variable)

Answer 26

a field of the class instead of a field of each class object

Question 27

static member method

Answer 27

a class method that is independent of class objects

Question 28

package

Answer 28

a grouping of related types, classes, interfaces, and subpackage

Question 29

fully qualified name

Answer 29

the concatenation of the package name with the class name using a period

Question 30

import statement

Answer 30

imports a package member into a file to enable use of the package member directly, without having to use the package member’s fully qualified name

Question 31

wildcard character

Answer 31

• imports all members of a package