Midterm

Question 1

Which of these is not a primitive data type in Java?
a. int
b. String
c. float
d. Boolean

Answer 1

b. String

Question 2

In System.out.println(“hello world”); System is a ________, println is a _________ and “hello world” is a _________
a. method, class, return-type
b. class, parameter, method
c. variable, method, parameter
d. class, method, parameter

Answer 2

d. Class, method, parameter

Question 3

The formula for the volume of a sphere is

Answer 3

V= 4/3πr^3

Question 4

In Java, the radius is saved as a double variable r. To calculate volume in Java we write
a. double v = 4Math.PIMath.pow(r, 3)/3;
b. double v = 4Math.PI()rrr/3;
c. double v = (4/3)Math.PIMath.pow(r, 3);
d. double v = (Math.PI()Math.pow(r, 3)4)/3;

Answer 4

a. double v = 4Math.PIMath.pow(r, 3)/3;

Question 5

Scanner x = new Scanner(System.in); How would be input an integer and save it in variable count.
a. int count = input.nextInt;
b. int count = input.nextInt();
c. int count = x.nextInt;
d. int count = x.nextInt();

Answer 5

d. int count = x.nextInt();

Question 6

The command to compile a file HelloWorld.java is

Answer 6

javac HelloWorld

Question 7

To use the debugger in Eclipse, we create _____________ in the program where execution will pause and allow us to inspect variables.

Answer 7

Breakpoints

Question 8

double x = 3.4567;
Which of these will print 3.46
a. System.out.print(x);
b. System.out.printf(“%.2f”, x);
c. System.out.printf(“%.3f”, x);
d. System.out.printf(“%f”, x);

Answer 8

b . System.out.printf(“%.2f”, x);

Question 9

Git is a

Answer 9

Version Control System

Question 10

double x = 31;
int y = 10;

Which of these will print Happy Halloween 10/31
a. System.out.printf(“Happy Halloween %d/%f”, y, x);
b. System.out.printf(“Happy Halloween %f/%d”, y, x);
c. System.out.printf(“Happy Halloween %d/%.0f”, y, x);
d. System.out.printf(“Happy Halloween %.0d/%f”, y, x);

Answer 10

c. System.out.printf(“Happy Halloween %d/%.0f”, y, x);

Question 11

What is the Git command git innit used for?

Answer 11

Initializes a local git repository

Question 12

What is the Git command git commit used for?

Answer 12

Takes everything thats in the index/staging area and commits it to the local repository

Question 13

Who created Git?

Answer 13

Linus Torvalds and the Linux community

Question 14

What is version control?

Answer 14

The tracking and managing of changes to software code

Question 15

What does the Git command git add <file> used for?</file>

Answer 15

Adds the selected files to the staging area of the index, ready not to be commit

Question 16

What is the Git command git status used for?

Answer 16

Checks what you have in the index/staging area, shows the differences between the working tree and the staging area

Question 17

What is the Git command git push used for?

Answer 17

Pushes the local repository you have created and pushes it to a remote repository

Question 18

What is the Git command git pull used for?

Answer 18

Pull the latest version from a remote repository

Question 19

What is the Git command git clone used for?

Answer 19

Clones the repository into a new directory

Question 20

The java compiler translates a .java file to generate a _____ file (what file extension for the created file?)

Answer 20

.class file

Question 21

What command line command, reports the version of the Java compiler installed?

Answer 21

javac -version

Question 22

What command line command, reports the version of the Java Runtime Environment installed?

Answer 22

java -version

Question 23

When working in Eclipse, to edit and compile code you use the _____.

Answer 23

Editor or Workbench

Question 24

What is the default file extension for UMLet diagrams?

Answer 24

.UXF

Question 25

What does this line of code do? int value1 = Integer.parseInt("42");

Answer 25

42 is a string, parseInt(String) converts it into an int

Question 26

T/F - A string variable can hold digits such as account numbers and zip codes

Answer 26

True

Question 27

Declaring a class does create actual objects

Answer 27

True

Question 28

The data components of a class that belong to every instantiated object are the class's _____ variables

Answer 28

Instance

Question 29

The access specifier in the declaration of instance variables should be _______

Answer 29

private

Question 30

A method header consists of which of the following parts?

Answer 30

An access specifier, a return type, a method name, and a list of parameters

Question 31

By using _________ you can use reasonable, easy-to-remember names for methods and concentrate on their purpose rather than on memorizing different method names

Answer 31

method overloading

Question 32

What does static do in a class?

Question 33

Which operator computes the remainder of an integer division?

Answer 33

%

Question 34

a ________ evaluation is where each part of an expression is evaluated only as far as necessary to determine whether the entire expression is true or false

Answer 34

Short circuit

Question 35

Area of a circle

Answer 35

πr^2

Question 36

circumference of a circle

Answer 36

2πr

Question 37

Volume of a rectangular prism

Answer 37

L*W*D

Question 38

Volume of a cone

Answer 38

πr^2h/3 or (1/3)πr^2h

Question 39

The command to compile a file HelloWorld.java is

Answer 39

javac HelloWorld.java

Question 40

In flowcharts, input and output is always shown in ________

Answer 40

Parallelograms

Question 41

Breaking large sequences of processing steps into smaller, reusable units in a computer program

Answer 41

Functional decomposition

Question 42

Methods are also known as

Answer 42

Modules

Question 43

Arguments are the actual inputted variable form of

Answer 43

parameters

Question 44

Variables declared inside of a method body are part of that methods _____ and are not visible in other method bodies

Answer 44

local scope

Question 45

a _____ is a blueprint for an ________

Answer 45

Class, Object

Question 46

What is an object?

Answer 46

an object is an allocation of memory that contains properties and behaviours

Question 47

Each object is also called is also called an _____ of the class

Answer 47

instance

Question 48

A property is usually a

Answer 48

adjective

Question 49

An object is typically a

Answer 49

noun

Question 50

A (behaviour) method is typically a

Answer 50

verb

Question 51

A UML Class Diagram looks like a rectangle or column with __ rows

Answer 51

3

Question 52

A UML Class Diagram record the _____ and _____ for a class

Answer 52

Properties and behaviours

Question 53

Instance variables are declared at the _____ level

Answer 53

Class

Question 54

a java object property/attribute is implemented using 3 things:

Answer 54

Instance variable, accessor and mutator

Question 55

2 Ways to identify a constructor

Answer 55

1. Same name as class 2. No return type

Question 56

Primitive types: name the groups

Answer 56

4 Numeric no INT Byte Short Int Long 2 numeric with INT Float Double 1 Logic Bool 1 Numeric storing letters Char

Question 57

Bits of memory Byte Short Int Long

Answer 57

8, 16, 32, 64

Question 58

Should you use float or double for money calculations?

Answer 58

Neither

Question 59

You cannot assign a ____ to a ____ or vice versa

Answer 59

Char, String

Question 60

What does keyword static cause to happen when applied to a class-level variable?

Answer 60

The variables becomes part of the class and is shared by any instance

Question 61

Why do we use static and final for class-level constants?

Answer 61

The value never changes, so to save memory we only keep one copy of value in memory (static)

Question 62

A reference type variable contains a ______ not a ______

Answer 62

reference-value, object

Question 63

x=5 y=10 x++ =? ++y= x++ + ++y =?

Answer 63

6, 10, 16 since x++ takes place after the equation

Question 64

outputs Print ("test" + 1 + 2) Print(1 + 2 + "test")

Answer 64

test12 3test