Chapter 2

Question 1

in a program are used to store data such as numbers and letters. They can be thought of as containers of a sort. The number, letter, or other data

Answer 1

Variabels

Question 2

To know the name of the variable, how much computer memory to reserve for the variable, and how the data item in the variable is to be coded as strings of 0s and 1s. You give this information in

Answer 2

variable declaration

Question 3

The variable can hold whole numbers, such as 42, −99, 0, and 2001. A whole number is called

Answer 3

Integer

Question 4

What is a data type for objects of a class called?

Answer 4

class type

Question 5

How many primitive type do we have ?

Answer 5

8

Question 6

Which Primitive Type has the range of -128 to 127

Answer 6

byte

Question 7

Which Primitive Type has the range of -32,768 to 32,767 ?

Answer 7

short

Question 8

Which Primitive Type has the range of -2,147,483,648 to 2,147,483,647

Answer 8

int

Question 9

Which Primitive Type has the range of -9,223,372,036,8547,75,808 to 9,223,372,036,854,775,807

Answer 9

Long

Question 10

What kind of value is char?

Answer 10

Single character (Unicode)

Question 11

What kind of value is float?

Answer 11

floating-point

Question 12

How much memory does boolean use?

Answer 12

1 bit

Question 13

Which Primitive Type has the range of ±3.40282347 × 10 +38 to ±1.40239846 × 10 −45

Answer 13

Float

Question 14

Which Primitive Type has the range of ±1.79769313486231570 × 10 +308 to ±4.94065645841246544 × 10 −324

Answer 14

double

Question 15

Which Primitive Type has the range of 0 to 65,535

Answer 15

char

Question 16

How many floating point do we have?

Answer 16

2

Question 17

A number having a fractional part—such as the numbers 9.99, 3.14159, −5.63, and 5.0—is called

Answer 17

floating-point number

Question 18

As with integer types, the differences between float and double involve the range of their values and their storage requirements. If you cannot decide between the types float and double, use

Answer 18

double

Question 19

Are these legal identifier? inputStream, YourClass, CarWash, hotCar, theTimeOfDay

Answer 19

yes

Question 20

We will always follow the convention that the names of classes start with

Answer 20

Upper case letter

Question 21

the names of variables and methods start with

Answer 21

lower case letter

Question 22

Are these legal identifier prenhall.com, go-team, Five*, 7eleven ?

Answer 22

No

Question 23

What is wrong with this identifier prenhall.com ?

Answer 23

It has a dot in it

Question 24

What is wrong with this identifier go-team ?

Answer 24

It has a hyphen in it

Question 25

What is wrong with this identifier Five* ?

Answer 25

it has an asterisk in it

Question 26

What is wrong with this identifier 7eleven ?

Answer 26

it starts with a digit

Question 27

Some words in a Java program, such as the primitive types and the word if, are called

Answer 27

keywords or reserved words

Question 28

All Java keywords are entirely in what case?

Answer 28

lower case

Question 29

main and println are not keywords, then what are they?

Answer 29

predefined meaning

Question 30

What does predefined meaning mean?

Answer 30

you can change their meaning, but it is a bad idea to do so

Question 31

The most straightforward way to give a variable a value or to change its value is to use

Answer 31

assignment statement

Question 32

What does the “ = “ equal sign called?

Answer 32

assignment operator

Question 33

The computer evaluates what side of the “ = “ sign in an expression, right or left?

Answer 33

right

Question 34

A variable that has been declared, but that has not yet been given a value by an assignment statement called

Answer 34

uninitialized

Question 35

If the variable is a variable of a class type, it literally has no value. If the variable has a primitive type, it likely has some

Answer 35

default value

Question 36

This line must appear before the first statement that takes input from the keyboard. That statement in our example is

Answer 36

Scanner keyboard = new Scanner(System.in);

Question 37

What does this line do keyboard.nextInt() ?

Answer 37

reads one int value from the keyboard.

Question 38

System is a ____ that is part of the Java language, and out is ___

Answer 38

class, object

Question 39

What does this called 865000000.0. in a Floating-point?

Answer 39

scientific notation

Question 40

what is it public static final double PI = 3.14159; called?

Answer 40

Constants

Question 41

You can assign a value of any type on the following list to a variable of any type that appears further down on the list called:

byte → short → int → long → float → double

Answer 41

Assignment Compatibilities

Question 42

a _____ changes the data type of a value from its normal type to some other type.

Answer 42

type casting

Question 43

What are the 5 Arithmetic Operators?

Answer 43

+ - / * and %

Question 44

A __ has two operands, such as the operators + and * in

Answer 44

binary operator

Question 45

A string can even have zero characters. Such a string is called

Answer 45

empty string and is written as a pair of adjacent double quotes, like so:” “.

Question 46

You can connect or join or paste two strings together to obtain a larger string using +, called:

Answer 46

concatenation

Question 47

Any characters that are not visible when displayed are collectively known as

Answer 47

whitespace

Question 48

What is this "Java" called?

Answer 48

Escape Characters

Question 49

" Double quote. ' Single quote. \ Backslash.

\n New line. Go to the beginning of the next line.

\r Carriage return. Go to the beginning of the current line. \t Tab. Add whitespace up to the next tab stop. are example of ?

Answer 49

Escape Characters

Question 50

A method works like the print method except it allows you to add formatting instructions that specify things such as the number of digits to include after a decimal point.

Answer 50

printf

Question 51

This is called /** ?

Answer 51

javadoc

Question 52

This is called /* */ ?

Answer 52

long comment