Chapter 2 - Input/Output and Operators

Question 1

// does what in a program ?

Answer 1

end-of-the-line comment

Question 2

/*

Answer 2

traditional comment

Question 3

declare a class

Answer 3

public class Class{}

Question 4

what two things must be the same in java in order for the application to run?

Answer 4

the class name and the file name

Question 5

sample code that prints out “Hello World”

Answer 5

System.out.print(“Hello World”);

Question 6

system.out.printIn

Answer 6

prints output followed by new line

Question 7

system.out.print

Answer 7

prints output without a new line

Question 8

system.out.printf

Answer 8

displays formatted data

Question 9

%s

Answer 9

string

Question 10

%d

Answer 10

is a format placeholder for int (integer)

Question 11

%f

Answer 11

double and float

Question 12

%b

Answer 12

boolean

Question 13

%n

Answer 13

newline

Question 14

%t

Answer 14

tab

Question 15

%20 does what?

Answer 15

creates a 20-character position, right justified

Question 16

what code does a java program need in order to read user input?

Answer 16

import java.util.Scanner

Question 17

what code creates a scanner object in java?

Answer 17

Scanner input = new Scanner (System.in)

Question 18

what code reads user input as a double value?

Answer 18

double number1 = input.nextDouble();

Question 19

what code reads as an integer?

Answer 19

int number1 =input.nexInt();

Question 20

what code reads user input as a string ?

Answer 20

String myvalue = input.nextLine();

Question 21

float vlaue

Answer 21

flloat number1=input.nextFloat();

Question 22

Boolean

Answer 22

boolean myvalue = input.nextBoolean();

Question 23

compile a program

Answer 23

javac Program1.java

Question 24

execute a program

Answer 24

java Program1

Question 25

code for instant variable

Answer 25

private String name;

Question 26

instance variable

Answer 26

because it is private only certain classes can access it

Question 27

local variable

Answer 27

public void setName(String name){this.name = name;}

Question 28

local variable definition

Answer 28

a variable that is declared within a method and cannot be accessed by statements that are outside the method

Question 29

primitive types

Answer 29

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

Question 30

nonprimitive

Answer 30

reference types

Question 31

set method code

Answer 31

public void setName(String name){ this.name=name;}

Question 32

get method code

Answer 32

public String getName(){ return name;}

Question 33

what is a constructor

Answer 33

implicitly by the new operator

Question 34

two things that must be the same in a constructor to avoid syntax errors

Answer 34

class name and constructor name

Question 35

sequential execution

Answer 35

one after the other