COSC 117

Question 1

What is a do-while loop

Answer 1

it is a loop that always executes at least onces

Question 2

How to loop through a string?

Answer 2

String original=keyboard.nextLine();
String revisted=’’’;
for(int i=0;i<orginal.length(); i++)
char c=original.charAt(i);

Question 3

How to write a switch statement using months, that would be read in by the user? The first and second month are the same.

Answer 3

int month=keyboard.nextInt();
switch(month){
case 1: case 2:
break;
case 3:
break;
default:

Question 4

What is the purpose of methods?

Answer 4

reuse
separation of concerns
test it on its own

Question 5

How to write a method?

Answer 5

public static int sum(int x, int y){
int result=x+y;
return result;
}

Question 6

How to create a random number?

Answer 6

Random rand=new Random();
int num=rand.nextInt(x);

Question 7

What is the range of numbers?
Random random=new Random();
int num=random.nextInt(10);

Answer 7

0-9

Question 8

What is the range of numbers?
Random random=new Random();
int num=random.nextInt(9)+1;

Answer 8

1-9

Question 9

What is the range of numbers?
Random random=new Random();
int num=random.nextInt(5)+random.nextInt(3)+7;

Answer 9

7-13

because 4+2+7=13 and then the +7 means it starts at 7

Question 10

How to read in information from the user?

Answer 10

Scanner keyboard=new Scanner(system.in);
int num=keyboard.nextInt();

Question 11

What is primary(ram) memory?

Answer 11

is temporary lost when turned off

Question 12

What is secondary memory?

Answer 12

permanent, even without power.

Examples: hard disk, USB, CD

Question 13

What is an expression?

Answer 13

always evaluates to a value

Question 14

Is keyboard.nextDouble() an expression?

Answer 14

yes

Question 15

is 23.09 an expression?

Answer 15

yes

Question 16

is “HELLO WORLD” an expression?

Answer 16

yes

Question 17

What type of code is LOD Y
SUB X
STO T1

Answer 17

assembler code

Question 18

What is operator precedence?

Answer 18

the order which operations are done.
Example: 3+42
42 is done first

Question 19

What is the order of precedence for( !, ||, &&)

Answer 19

!
&&
||

Question 20

What are three different control structures?

Answer 20

sequence
branching (if statement)
iteration (loops)

Question 21

When is a for loop used? How do you write it?

Answer 21

used when you know how many times to run the loop

for(int i; i<; i++);

Question 22

Convert while loop to a for loop
while(count<numOfexams){
syso
count++;
}

Answer 22

for(int count=0; count<numOfexams; count++)

Question 23

What is 2%3?

Answer 23

2

Question 24

what is 6%6?

Answer 24

0

Question 25

what is 4%3?

Answer 25

1

Question 26

what is 4%5?

Answer 26

4

Question 27

What data types can be used to represent real numbers? not integer

Answer 27

double

float

Question 28

What is the purpose of an import statement? What is an example?

Answer 28

The purpose is to use other classes in java. For example when using the Scanner class you have to import the code from the scanner class.

Question 29

What is the purpose of a sentinel value?

Answer 29

The purpose of a sentinel value is to help determine when a while loop will end. For example
while(num!=-1)
the sentinel value is -1

Question 30

To declare a variable, two pieces of information need to be specified what are they?

Answer 30

data type (string, int, double...)
name of the variable (int x;)

Question 31

System.out.printf(“Output:%.2f”, 3.14158676686);

Answer 31

output: 3.14

Question 32

false || ! (false && !false)

Answer 32

true

Question 33

false || !( true && !false)

Answer 33

false

Question 34

true || !(false && !true)

Answer 34

true

Question 35

true || !(true && !true)

Answer 35

true

Question 36

What is the output?
int x=3;
int y=4;
Syso(x+y+ “equals”+ y+x);

Answer 36

7 equals 43

Question 37

Wrtie 4/3pieR^3

Answer 37

(4.0/3) Math.PI Math.pow(r,3);

Question 38

What is the output?

syso(“dogs "+ (2+1)+ “+ “+ “are\n smart”);

Answer 38

dogs”+(2+1)+are

smart

Question 39

name 8 data types

Answer 39

int
Boolean
float
short
long
byte
char

Question 40

how to check if two strings are equal?

Answer 40

use .equals();

Question 41

What is a variable’s scope?

Answer 41

it is where in the code a variable can be used.

For example when writing multiple methods the variable within each method can only be used in that method.

Question 42

How to declare an array?

Answer 42

int array[]=new int[x];

Question 43

How to initialize arrays?

Answer 43

int [] scores= {5,3,2,3,4,5,};

Question 44

In an applet, when drawing a line what are the numbers that are read in?

Answer 44

(int x1, int y1, int x2, int y2)

Question 45

In an applet, when drawing a shape what are the numbers that are read in?

Answer 45

(int x, int y, int width, int height)