Java

Front 1

What does "this" represent in getters and setters

Back 1

Denotes a reference to an implicit Parameter and to call another constructor of the same class

Front 2

A class typically contains what 3 things

Back 2

fields for data
constructors to create objects
methods getters and setters
in that order

Front 3

What does the get method do

Back 3

it only looks up the state of an object and reports on it

Front 4

What does the set and add method do

Back 4

modify the state of an object

Front 5

What are methods that change instance fields called

Back 5

mutator methods

Front 6

What are methods that only access instance fields called

Back 6

accessor methods

Front 7

What is a class

Back 7

A template or blueprint from which objects are made

Front 8

What are you doing when you construct an object from a class

Back 8

You have created an Instance of the class

Front 9

What is encapsulation

Back 9

Information hiding the implementation details from the user of an object

Front 10

What is Inheritance

Back 10

When you extend an existing class that has all the properties of an existing class and adds more to it

Front 11

What is the data in an object called

Back 11

Instance Fields

Or instance variables

Front 12

What are the procedures that operate on data called

Back 12

Methods

Front 13

What is the header of a class called MyProgram

Back 13

public class MyProgram{ }

Front 14

What does public mean

Back 14

It means its available to any other code in the program

Front 15

What does the reserved word void mean

Back 15

Indicates the method will not return a value

Front 16

When do you use the reserved word static

Back 16

When you want to keep track of some information shared by all the members of a class OR When it doesn't make sense to have more than one instance of a property or method

Front 17

What is an expression

Back 17

A piece of code that evaluates to a single value like 2 + 2

Front 18

What is a statement

Back 18

a full sentence that end with a semi-colon(;) For example:

a = 3;

Or

System.out.println("Java");

Front 19

How is encapsulation attained

Back 19

In the spirit of encapsulation it is common to make fields private. When instance data is private, that data can only be directly accessed from the that class. We still need access to these values however and that is done indirectly by adding public methods that obtain the field values for us.

Front 20

What do methods do

Back 20

They operate on objects and access their Instance Fields

Front 21

A method has two parameters and in dave.raisesalary(5) what are they called and which is which

Back 21

dave is the Implicit Parameter and the number inside the parentheses is the Explicit Parameter

Front 22

In every method what does the key word this imply

Back 22

That the word that follows is an implicit Parameter

Front 23

Does Math.pow(x , a) have an implicit parameter

Back 23

No because it does not use a math object to carry out its task. (It is a static method)

Front 24

What is Implicit in X.F(param)

Back 24

X is implicit and pram is explicit

Front 25

What are the 3 types of errors in programming

Back 25

Syntax errors

Logical errors

Runtime errors

Front 26

API

Back 26

application program interface is a set of routines protocols and tools for building software applications. A good API makes it easier to develop a program by providing all the building blocks. A programmer then puts the blocks together.

Front 27

Why is the header of a main method

Back 27

public static void main(String [] args){ }

Front 28

JVM

Back 28

Java Virtual Machine

Front 29

What is Java sensitive about

Back 29

Case Sensitive

Front 30

What are public and private called

Back 30

Access modifiers they control the level of access other parts of the program have to the code

Front 31

In terms of Java, what should the key word CLASS remind you of with this language?

Back 31

everything in Java lives in a class

Front 32

How should you think of a Class

Back 32

as a container for the program logic that defines the behavior of the application

Front 33

What follows the Class keyword

Back 33

The name of the class

Front 34

What must Class names start with and what can they be named

Back 34

The must begin with an uppercase letter after that they can be letters of numbers and the length is almost unlimited

Front 35

What are the standard naming conventions in a class

Back 35

Class names are nouns that start with upper case letters if its multiple words use camelback

Front 36

What names must match when it comes to classes

Back 36

The class name and the .java file (source code) must be the same

Front 37

What happens when you compile a file

Back 37

The compiler converts the source code into bytecode that the JVM can understand. During compilation syntax is checked and a .class file (byte-code) is created.

Front 38

What code does the compiler always start with

Back 38

the code in the main Method

Front 39

What is another term for Method

Back 39

function a methods performs some sort of function

Front 40

What method must you have in your source file for your class to run

Back 40

main method

Front 41

Do you declare the main method public, private, protected?

Back 41

Public

Front 42

What do braces generally denote

Back 42

parts usually blocks of code

Front 43

What ends each Java statement

Back 43

a semi colon and statements can span multiple lines

Front 44

How should you think of Java statements

Back 44

Sentences that end with a semi colon

Front 45

When calling methods what is the typical syntax

Back 45

object.method(parameters)

Front 46

What else are Parameters called

Back 46

arguments

Front 47

What is the minimum and maximum number of parameters

Back 47

zero to infinity

Front 48

If there are no parameters in a methods when must the method still have

Back 48

empty parenthesis

Front 49

Three ways of marking comments

Back 49

// single line comment

/*multiline comment*/

/**Javadoc comment*/

Front 50

What are the comment notation for automatic documentation

Back 50

/** this will be automatically documents */

Front 51

What is it called when every variable must declare type

Back 51

Strongly Typed Language

Front 52

What does the name Double type come from

Back 52

Refers to the fact that it has twice the precision of an int

An int is 32 bits a double is 64 bits

Front 53

How do you do quotes included in the sentence

Back 53

\" Like System.out.println("\"We will test this page test new line\"");

Front 54

What does every variable have and what order

Back 54

a type first then the name For example

double salary;

int vacationDays;

Front 55

What can you name a variable

Back 55

The first letter is a Letter and then letter and or numbers

Front 56

Can you have multiple variable declarations of the same page

Back 56

Yes but it is not recommended because of readability

Front 57

Are variable names case sensitive

Back 57

Yes you can have Variable and variable and the compiler thinks they are different variables

Front 58

What must you do after declaring a variable

Back 58

You must initialize it by means of an assignment statement

Front 59

When declaring variable what is considered good practice

Back 59

declare them as closely as possible to the point where they are going to first be used

Front 60

With variable what is the key word Final denote

Back 60

a constant which means you assign the variable once and then it is set once and for all

Front 61

What is the convention for naming variable constants

Back 61

ALL CAPS

Front 62

What is the shortcut to X = X + 4

Back 62

X +=4

Front 63

What gives Java its portability

Back 63

A computation should yield the same results no matter which virtual machine executes it

Front 64

How do you increment or decrement a variable

Back 64

n++ or n-- by one number

Front 65

What operator do we use to test for equality

Back 65

==

Front 66

What operator do we use to test for inequality

Back 66

!=

Front 67

How do you short circuit an expression being evaluated if the firsrt one doesn't evaluate

Back 67

expression1 && expression2 If the exp1 is shown to be false then exp2 is also false thus exp2 isn't evaluated Like x !=0 && 1/X. This will not allow a division be zero

Front 68

expression1 || expression2

Back 68

Condition first and if its true then exp1 is true if its not true then then exp2 is true Like x < y || X : Y

Front 69

Which class contains mathematical function and constants

Back 69

Math Class Like math.sqrt(x)

Front 70

There is a subtle difference between println and the math class what is it

Back 70

Println operates on an object the Math class does not and that is called static method

Front 71

What does HTTP stand for and what is it used for

Back 71

Hyper Text Transfer Protocol how to transfer data across the internet

Front 72

Annotations

Back 72

User to specify additional information about a Class or Interface LIKE they can be used to specify if the session is stateless or stateful they always start with @ sign

Front 73

GUI

Back 73

A graphical user interface (GUI) is a human-computer interface (i.e. a way for humans to interact with computers) that uses windows icons and menus and which can be manipulated by a mouse (and often to a limited extent by a keyboard as well).

Front 74

What does void represent

Back 74

The method does not return a value

Front 75

What else is a method called when you are not being lazy

Back 75

Method Declaration

Front 76

What is the first part of a method called (before the curly braces)

Back 76

Method Header

Front 77

What is the part of a method called that is inside the curly braces

Back 77

Method body

Front 78

What is the main method, and what other method can call it?

Back 78

They are recipes and the first method called into action when the program begins running. The main is never called by another method

Front 79

What is a STATEMENT?

Back 79

It is a sentence that tell the computer to do something like

system.out.println();

Front 80

The API is just a bunch of what?

Back 80

Code and the code perform actions for us that we can piece together to create a program

Front 81

What is the purpose of the Request object?

Back 81

It represent the data submitted by the browser

Front 82

What is the purpose of the Response object?

Back 82

It represents the response that we are sending back to the client

Front 83

What is the purpose of the Out object?

Back 83

Represents output stream for the page, the content that will be sent back to the browser as the body of its response

Front 84

What is the thing called that is stored in a variable?

Back 84

a Value

Front 85

AmountInAccount = 50.22;

What is this statement called?

Back 85

Assignment Statement

Front 86

What is MVC

Back 86

Model - View - Controller

Front 87

The instance fields hold values of an object the set of those values is what?

Back 87

Their current state of that object and when you invoke a method on that object the state me be changed also

Front 88

What is the key to making encapsulation work?

Back 88

Have methods that never have direct access to the objects instance fields

Front 89

What is the "cosmic superclass from which all others derive?

Back 89

Object Class

Front 90

When you are looking for what should be a class what is a simple rule of thumb?

Back 90

Look for Nouns in the problem analysis, like Item, Order, Shipping Address, Payment, etc

Front 91

When looking for what should be a method what is a good rule of thumb?

Back 91

They are Verbs Like Add item to order, Cancel payment, Change shipping address

Front 92

What , it called when a developer realizes that a method should never have been created in the first place?

Back 92

Deprecated, and it is a good idea to stay away from deprecated methods, since there are better ones to replace them with

Front 93

What is the deployment descriptor for the appilcation

Back 93

the Web.xml file

Front 94

What is the difference = or ==

Back 94

= is an assignment to a variable and == is an equality check

Front 95

Two type of data types?

Back 95

Primitives and References

Front 96

What are the primitive?

Back 96

byte, short, int, long, float, double, char, boolean

Front 97

What are the References?

Back 97

Arrays Classes and Interfaces

Front 98

What is the difference between these two
age = 16
newAge = ++age
newAge = age++

Back 98

the first one is still 17 because the pre-Increment increase the number before assigning. The second one assigns age to newAge first and then increments it

Front 99

What is the & sign

Back 99

And

Front 100

What is the | sign

Back 100

Or

Front 101

What is the ^ sign

Back 101

Exclusive or

Front 102

What is the ~ sign

Back 102

Compliment

Front 103

What is the ! symbol

Back 103

Not

Front 104

What is the && symbol

Back 104

The and symbol

If age<21 && hasId --java will not check the second condition if the first is not met

Front 105

What is the || symbol

Back 105

The or symbol

if the first condition is true it will not check the second condition

Front 106

What are the two conversions and what does it mean

Back 106

Implicit and Explicit
Implicit means the compiler will convert them automatically, explicit means you have to use the cast method

Front 107

How do you cast

Back 107

with parenthesis like
like (double) 5. now the number is double or 5.0

Front 108

What is the "\n" symbol?

Back 108

The new line escape character

Front 109

What is the "\t" symbol?

Back 109

The tab escape character

Front 110

How do you say 20 % 3 or i % 3

Back 110

20 mod 3 or i mod 3

Front 111

What are Strings

Back 111

They are reference types not primitives. String is a class therefore it is capitalized

Front 112

What are reference varibles

Back 112

Reference variables point to a location in memory. Java hides the pointers while some programs allow you to get the memory address

Front 113

When comparing two strings like

"java" and "java" what should you not use

Back 113

Do not use the == because it java checks the memory location not the actual string. Sometimes the compiler will store the same string in different memory locations. Remember strings point to memory locations. Use the stringbuilder method equals()

Front 114

When comparing two strings what method should you use

Back 114

"string".equals("string") instead of the == symbol. Remember strings are references to memory only. and the same string may be in different memory locations depending on the compiler

Front 115

Would this be true or false
"Java".equals("java")

Back 115

false, they are not equal because java strings are case sensitive and each of there references will be stored in different memories

Front 116

With strings like "Java".equals("java") what method can you use that makes this equal regardless of case

Back 116

equalsingnorecase, like

"Java".equalsIgnoreCase("java")

would make these equal

Front 117

What are items within an array called

Back 117

Elements

Front 118

In Arrays can there be mixed types or do all the types need to be the same?

Back 118

All the types are the same

Front 119

How are arrays referenced or referred to?

Back 119

via an index and it starts at zero

Front 120

What are the three ways to declare an array?

Back 120

int[] intArray;

String stringArray[];

object[] objectArray;

Front 121

When adding class constructors what is a good practice

Back 121

Start with a default constructor. public dog(){

YOU CAN ADD ALL OF YOUR DEFAULT VALUES HERE

}

Front 122

What are objects made from

Back 122

The Class. the blueprint.

Front 123

What defines an objects characteristics

Back 123

The Class. The bueprint

Front 124

What is an Entity?

Back 124

It is an object -- the house, and the house was built from the Class--the blueprint

Front 125

Can you have two methods with the same name

Back 125

Yes but the parameter requirements must be different

Front 126

Can we have two constructors in a Class

Back 126

Yes like a default constructor which contains the fields defaulted

Front 127

What is it called when you can have more than one method with the same name BUT different parameters

Back 127

Method Overloading

Front 128

Can you call the same method with different parameters (method overload) from the other method with the same name?

Back 128

Yes e.g. you can can call eat() from eat(String food) method

Front 129

What does static mean?

Back 129

General to the class and not specific to an object or instance.

Front 130

What does the final modifier mean

Back 130

It's a constant

Front 131

What is an overloading constructor?

Back 131

It's a Class that has more than one constructor, of course of the same name because all constructors have the name of the class

Front 132

When is this() used?

Back 132

When you are in a overloaded constructor and you want to call the default constructor

Front 133

Given:

Cat c2 = new Cat();

What is the c2 called?

Back 133

Instance Variable Name

Front 134

What is any part of Java that has a value

Back 134

An Expression

Front 135

Any variable that is not a primitive type is what type?

Back 135

A reference variable