Scjp 6 - Chapter 1

Front 1

start with: a letter, $, underscore

Front 2

What are JavaBeans?

Back 2

Java classes that have properties.

Front 3

JavaBeans methods

Back 3

camelCase and prefixed with set, get, is, add, remove

Front 4

JavaBeans properties

Back 4

private instance variables accessed with getter and setters

Front 5

JavaBeans Events

Back 5

The JavaBean spec supports events, which allow components to notify each other when something happens.

Front 6

JavaBeans: add a listener

Back 6

prefix add, followed by the listener type. Ex: addActionListener()

Front 7

JavaBeans: remove a listener

Back 7

prefix remove, followed by the listener type. Ex: removeActionListener()

Front 8

JavaBeans: Listener method names suffix?

Back 8

must end with the word "Listener"

Front 9

How many public classes per source code file?

Back 9

1

Front 10

What is necessary of public class name?

Back 10

Must match the name of the source file

Front 11

The package statement must be the first line in the source code file, before any import statements that may be present.

Front 12

Files with no public classes can have a name that does not match any of the classes in the file.

Front 13

class access levels (4P)

Back 13

public, protected, package (default), private

Front 14

class access modifiers (3P)

Back 14

public, protected, private

Front 15

class non-access modifiers (AFN3STV)

Back 15

abstract, final, native, static, synchronized, strictfp, transient, volatile

Front 16

** Class Access

Front 17

How to access a class?

Back 17

Create an instance of class B. Extend class B. Access methods and variables.

Front 18

class package (default) access

Back 18

No modifiers. Can be seen only by classes within the same package.

Front 19

class public access

Back 19

All classes have access to a public class.

Front 20

class: strictfp

Back 20

A class or a method (never a variable) will conform to the IEEE 754 standard rules for floating points.

Front 21

class: final classes

Back 21

the class can't be subclassed

Front 22

abstract classes

Back 22

can never be instantiated, only extended

Front 23

Can you mark a class as both abstract and final?

Back 23

No

Front 24

interface description

Back 24

A contract for what a class can do, without saying anything about how the class will do it.

Front 25

interface access

Back 25

implicitly abstract, can be default or public

Front 26

interface method access

Back 26

implicitly public and abstract, not static, final, strictfp or native

Front 27

interface variable access

Back 27

public static final - i.e. constants - don't have to be declared

Front 28

interface can extend other interfaces?

Back 28

Yes and only other interfaces

Front 29

interface can be used polymorphically?

Back 29

Yes

Front 30

class member access modifiers

Back 30

public, protected, package (default), public

Front 31

class member: two different access issues

Back 31

access and inheritance

Front 32

class member is public

Back 32

all other classes can access the member

Front 33

class member is private

Back 33

can only be accessed in the class it was declared

Front 34

class member is default (package)

Back 34

can only be accessed in the same package

Front 35

class member is protected

Back 35

can only be accessed through inheritance or in the same package

Front 36

class: protected member access from other instance in same class

Back 36

The protected member becomes private.

Front 37

class member: Can access modifiers be applied to local variables?

Back 37

No. (the only modifier that can be used is final)

Front 38

class member: final methods

Back 38

prevents a method from being overridden in a subclass

Front 39

class member: final arguments

Back 39

can't be modified

Front 40

class member: abstract methods

Back 40

not implemented, without method body, makes the class abstract

Front 41

class member: The first concrete subclass of an abstract class must implement all abstract methods of the superclass

Front 42

class member: abstract cannot be combined with

Back 42

private, final or static

Front 43

synchronized methods

Back 43

A method can be accessed by only one thread at a time. Applies only to methods.

Front 44

class member: the synchronized modifier can be matched with

Back 44

any of the four access control levels

Front 45

class member: native methods

Back 45

Indicates that a method is implemented in platform-dependent code. Applies only to methods. Note that a native method's body must be a semicolon (like abstract methods), indicating that the implementation is omitted.

Front 46

strictfp methods

Back 46

Strictfp forces floating points to adhere to the IEEE 754 standard

Front 47

Methods with Variable Argument Lists (var-args)

Back 47

Must be the last and only parameter. Syntax <type>... <id>.

Front 48

class member: Non-allowed modifiers

Back 48

abstract, final and static

Front 49

class member: Two types of variables

Back 49

primitives and reference variables

Front 50

Primitives 8 types

Back 50

char boolean INTEGER(byte short int long) FLOAT(float double) : integers and floats are signed

Front 51

integer sizes and ranges

Back 51

8,16,32,64 : -2^(n-1) - 2^(n-1)-1

Front 52

float sizes and ranges

Back 52

32,64 : n/a

Front 53

char size

Back 53

16

Front 54

primitives and refs 4 declarations

Back 54

static instance parameters local

Front 55

instance variables access levels

Back 55

4P

Front 56

instance variables non-access modifiers (FTV)

Back 56

final, transient, volatile

Front 57

Local variables are declared

Back 57

in a method. They are on the stack.

Front 58

local variables non-access modifiers (F)

Back 58

final

Front 59

Local variables don't get default values

Front 60

array declarations

Back 60

On the heap. <type>[] <identifier> or <type> <identifier> []

Front 61

int[5] score

Back 61

Good or Bad?

Front 62

final variables

Back 62

Makes it impossible to reinitialize that variable once it has been initialized with an explicit value. There are no final objects, only final references

Front 63

transient variables

Back 63

Don't serialize.

Front 64

volatile variables

Back 64

Always check the master copy of the variable. Applies only to instance variables.

Front 65

static variables and methods

Back 65

Can also be applied to class nested class, initialization blocks

Front 66

** Declaring Enums

Back 66

enum <TypeName> {CONST1, CONST2, } (semicolon at the end is optional). Can be declared inside or outside of classes, but not in methods.

Front 67

enums access modifiers

Back 67

public or package

Front 68

enums inside class

Back 68

Enclosing class name required in dereferencing.

Front 69

enums: constant specific class body

Back 69

A method specific to a constant that overrides a method defined in the enum.