Chapter 2: Using Objects

Question 1

object

Answer 1

A value of a class type.

Question 2

methods

Answer 2

A sequence of statements that has a name, may have parameter variables, and may return a value. A method can be invoked any number of times, with different values for its parameter variables.

Question 3

class

Answer 3

A programmer-defined data type.

Question 4

variable

Answer 4

A symbol in a program that identifies a storage location that can hold different values.

Question 5

initialize

Answer 5

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

Question 6

integer

Answer 6

A number that cannot have a fractional part.

Question 7

floating-point numbers

Answer 7

A number that can have a fractional part.

Question 8

case sensitive

Answer 8

Distinguishing upper- and lowercase characters.

Question 9

reserved words

Answer 9

A word that has a special meaning in a programming language and there-
fore cannot be used as a name by the programmer.

Question 10

comments

Answer 10

An explanation to help the human reader understand a section of a program; ignored by the compiler.

Question 11

uninitialized variable

Answer 11

A variable that has not been set to a particular value. In Java, using an uninitialized local variable is a syntax error.

Question 12

public interface

Answer 12

The features (methods, variables, and nested types) of a class that are accessible to all clients.

Question 13

argument

Answer 13

A value supplied in a method call, or one of the values combined by an operator.

Question 14

void

Answer 14

A reserved word indicating no type or an unknown type.

Question 15

overloading

Answer 15

Giving more than one meaning to a method name.

Question 16

construction

Answer 16

Setting a newly allocated object to an initial state.

Question 17

accessor method

Answer 17

A method that accesses an object but does not change it.

Question 18

mutator method

Answer 18

A method that changes the state of an object.

Question 19

API documentation

Answer 19

Information about each class in the Java library.

Question 20

packages

Answer 20

A collection of related classes. The import statement is used to access one or more classes in a package.

Question 21

object reference

Answer 21

A value that denotes the location of an object in memory. In Java, a variable whose type is a class contains a reference to an object of that class.

Question 22

frame

Answer 22

A window with a border and a title bar.

Question 23

component (User-interface component)

Answer 23

A building block for a graphical user interface, such as a but- ton or a text field. User-interface components are used to present information to the user and allow the user to enter information to the program.

Question 24

cast

Answer 24

Explicitly converting a value from one type to a different type. For example, the cast from a floating-point number x to an integer is expressed in Java by the cast notation (int) x.

Question 25

inner class

Answer 25

A class that is defined inside another class.