Java Concepts 3 - Implementing Classes

Question 1

abstraction

Answer 1

The process of finding the essential feature set for a building block of a program such as a class.

Question 2

access specifier

Answer 2

A keyword that indicates the accessibility of a feature, such as private or public.

Question 3

documentation comment

Answer 3

A comment in a source file that can be automatically extracted into the program documentation by a program such as javadoc.

Question 4

encapsulation

Answer 4

The hiding of implementation details

Question 5

garbage collection

Answer 5

Automatic reclamation of memory occupied by objects that are no longer referenced.

Question 6

initialization

Answer 6

Setting a variable to a well-defined value when it is created.

Question 7

instance field

Answer 7

A variable defined in a class for which every object of the class has its own value.

Question 8

javadoc

Answer 8

The documentation generator in the Java SDK. It extracts documentation comments from Java source files and produces a set of linked HTML files.

Question 9

JDK

Answer 9

The Java software development kit that contains the Java compiler and related development tools.

Question 10

local variable

Answer 10

A variable whose scope is a block

Question 11

constructor

Answer 11

A special block of statements called when an object is created

Question 12

test class

Answer 12

a second class, with a main method, to execute test instructions.

Question 13

public interface

Answer 13

The features (methods, fields) of a class that are accessible to all users

Question 14

return type

Answer 14

The type of the primitive or object that will be returned at the completion of a method

Question 15

//

Answer 15

single line comment, comments out the rest of the line to the right of the //

Question 16

In standard Java documentation, what needs to be commented?

Answer 16

every class, every method, every parameter, every return value

Question 17

lifetime

Answer 17

how long a variable lives and is accessible

Question 18

/* */

Answer 18

multi-line comment, comments out everything between the /* (starting) and the */ (ending)

Question 19

black box

Question 20

explicit parameter

Question 21

implement

Question 22

implicit parameter

Answer 22

the object on which a method is invoked

Question 23

method

Answer 23

a sequence of statements that has a name, may have formal parameters, and may return a value

Question 24

method body

Answer 24

the part of the method that contains the declarations of local variables and the statements.

Question 25

method definition

Answer 25

consists of an access specifier, the return type, the name of the method, a list of the parameters (if any), and the body of the method

Question 26

method signature

Answer 26

the name of a method and the types of its parameters

Question 27

method header

Answer 27

the return type and the method signature

Question 28

object-oriented

Answer 28

a paradigm that uses objects to design applications and computer programs

Question 29

parameter variable

Answer 29

a variable of a method that is initialized with a parameter value when the method is called

Question 30

private

Answer 30

a feature that is accessible only by methods of the same class or an inner class

Question 31

public

Answer 31

a feature that is accessible by all classes

Question 32

protected

Answer 32

a feature that is accissible by a class, its inner classes, its subclasses, and other classes in the same package

Question 33

return

Answer 33

a keyword that passes a value or object back to the calling method

Question 34

this

Answer 34

a keyword that is used like a pronoun to access the current object, usually the object on which the initial method was called

Question 35

type

Answer 35

a named set of values and the operations that can be carried out with them

Question 37

/** */

Answer 37

Javadoc comment, information inbetween these symbols can be automatically pulled out of the .java file to create the public interface. Ignored during compiling

Question 38

scope

Answer 38

the part of a program in which a variable is defined and accessible