Final- Java Basics ppt

Question 1

Sample program

Answer 1

public class NameWithSameNameAsFile
{

public static void main (String[] args)
{
System.out.println(“Happy Thanksgiving!”);

} //end main
} //end class

Question 2

data types (5)

Answer 2

int, double, boolean, char, String

Question 3

int

Answer 3

whole numbers

Question 4

double

Answer 4

numbers with a decimal point

Question 5

boolean

Answer 5

true or false

Question 6

char

Answer 6

use ‘ ‘ to enclose a single character

Question 7

String

Answer 7

Not a primitive type, notice the capital S. Use “ “

Question 8

For naming, the first character can be

Answer 8

a letter, underscore, or $

Question 9

Subsequent characters may be

Answer 9

letters, numbers, underscores, or $

Question 10

variable names cannot be

Answer 10

keywords

Question 11

Are names case-sensitive?

Answer 11

yes.

Question 12

constant names should be

Answer 12

ALLCAPS

Question 13

variable names

Answer 13

shouldBeLikeThis

Question 14

Variables and constants will be declared

Answer 14

at the beginning of the method.

Question 15

Variable and constant declaration looks like this:

Answer 15

final int MAX_HOURS = 18; 
String name;     
int age;       
double gradePointAvg;   char status;  
boolean active;

Question 16

You can initialize a variable as well. This means…

Answer 16

to include a value for each variable with the declarations. 
Example:
String name ="Spongebob”;   
int age = 5; 
double gradePointAvg = 3.0;
char status = ‘C’; 
boolean active = true;

Question 17

normal arithmetic operators

Answer 17

*

Question 18

division

Answer 18

/
If both operands int, returns an int.
If at least one operand double, returns a double.

Question 19

Modulus

Answer 19

%

Remainder or leftovers from division.

Question 20

3%10=

Answer 20

1

Question 21

5/10=

Answer 21

0

Question 22

5.0/10=

Answer 22

0.5

Question 23

used for input from the keyboard

Answer 23

Scanner class

Question 24

to let Java know that you are going to use the Scanner class

Answer 24

add import statement to top of program

Question 25

import statement for Scanner class

Answer 25

import java.util.Scanner;

Question 26

After adding the import statement, you must next

Answer 26

declare an object in the method that is linked to input from the keyboard

Question 27

Object declared to link input from the keyboard:

Answer 27

//declare a Scanner object
Scanner scan = new Scanner (System.in);

Question 28

Scanner methods

Answer 28

used in conjunction with scanner objects to get input

Question 29

Scanner methods (list dem)

Answer 29

nextLine() for String
nextInt() for integers
nextDouble() for doubles
NOTE: NO boolean or char

Question 30

Example of program that asks for your name and then prints “Hi your name”

Answer 30

import java.util.Scanner;
public class UsingScanner
{

public static void main (String[] args)
{
//declare a Scanner object
Scanner scan = new Scanner (System.in);

//declare a variable for name
String name;

//ask user for name
System.out.println("What is your name?");

//use Scanner to get the name and store it in the variable
name = scan.nextLine ();

//print statement
System.out.println ("Hi"+name);
}
}

Question 31

Ask person’s name & age.
Calculate 10 years younger.
Print a nice message.

Answer 31

import java.util.Scanner;
public class UsingScanner
{
public static void main (String[] args)
{
//declare a Scanner object
Scanner scan=new Scanner(System.in);
String name;

int age;
int lookLike = 0;

System.out.println ("What's your name?");

name=scan.nextLine();

System.out.println("What's your age?");

age=scan.nextInt();

lookLike = age-10;

System.out.println ("Wow " +name+ " you barely look "+lookLike+ " to me!"); } }