Chapter 2: Barons Bk

Question 1

An object is characterized by its

Answer 1

STATE and BEHAVIOR

•an object is an idea

Question 2

Object reference

Answer 2

A variable that represents an object

Question 3

State and behavior of objects

Answer 3

Data fields (instant variables) provide the current STATE
•Methods provide the BEHAVIOR and the operations that manipulate the object

Question 4

Encapsulation

Answer 4

Combining an object’s data and methods into a single unit (class)

Question 5

Class

Answer 5

A software blueprint that IMPLEMENTS OBJECTS of a given type

•several things can be created/ manipulated by a class

Question 6

@param

Answer 6

• @param=parameters

* all are instance methods

Question 7

Public

Answer 7

ACCESS SPECIFIER

Declaration that the class is usable by ALL client programs

•if not public, class can only be used in its own package

Question 8

Object

Answer 8

What is being created/ manipulated in a program (with the operations that manipulate it)

Question 9

Private

Answer 9

Keyword that implements info hiding (restriction of access)

Question 10

Private methods and variables can only be accessed

Answer 10

By methods of that class

Question 11

Constructor

Answer 11

(Method)

Creates an object of the class. It’s name = class name, no return type (void)

Question 12

Several constructors provide

Answer 12

Diff ways of initializing class objects

Question 13

Accessors

Answer 13

ACCESS METHOD: accesses an object w/o altering it, returns some info about object

Question 14

. Operator (dot operator)

Answer 14

Invokes accessor and mutator method

Indicates that a method is of a specific class

Question 15

Mutator method

Answer 15

Changes the state of an object by modifying at least one of its instance variables

Question 16

Instance methods

Answer 16

Operate on individual objects of a class
Ex: constructors, accessors, mutators

Question 17

Static methods

Answer 17

(Class methods) performs an operation for the entire class

Question 18

If a code calls an instance method or a private instance variable for a nonexistent object

Answer 18

Syntax error occurs

Question 19

Overloaded methods

Answer 19

2 or more methods in the same class that have the same name but diff parameter lists

Question 20

The compiler figures out which method the call by examining

Answer 20

The methods signature

Question 21

Signature

Answer 21

Consists of the method’s name and a list of the parameter types

Question 22

Example of overloading

Answer 22

More than one constructor in the same class

Question 23

Overloading constructors provide a choice of ways to

Answer 23

Initialize objects of the class

Question 24

Scope

Answer 24

Where can you use the variable? Where is it appropriate?

The region in which that variable or method is visible and can be accessed

Question 25

Block

Answer 25

{ }

Question 26

Implicit parameter

Answer 26

The particular object in which an instance method is called for. =keyword THIS

Question 27

Primitive data types

Answer 27

(Numerical) int, double, char, Boolean, float

Question 28

Reference data types

Answer 28

Objects

Question 29

Primitive data types vs reference data types

Answer 29

Diff = the way they are stored

Question 30

Aliasing

Answer 30

Having 2 references for the same object

Question 31

Null reference

Answer 31

(Null pointer) an uninitialized object variable

Question 32

Null

Answer 32

Keyword used to test whether a variable refers to an object or is uninitialized

Question 33

Method header

Answer 33

Defines the PARAMETERS of that method

Question 34

Actual parameters

Answer 34

ARGUMENTS

have values supplied by a particular method call in a client program

Question 35

Formal parameters

Answer 35

Explicit parameters (in word form) PLACEHOLDERS for the actual parameters