Java Unit 1

Question 1

These rules specify the basic vocabulary of the language and how programs can be constructed using things like loops, branches, and subroutines.

Answer 1

Syntax

Question 2

A set of rules that determine the meaning of a program written in a language.

Answer 2

Semantics

Question 3

Java programs are compiled into what?

Answer 3

Byte code!

Question 4

What is a subroutine call statement?

Answer 4

A subroutine call statement is a predefined set of routines for a subroutine to complete.
Example: System.out.println is a subroutine.

Question 5

In order to define a program, a class must include a subroutine named?

Answer 5

main
public static void main(String[] args) {
statements
}

Question 6

Why do you have to type “public” in the first line of main()?

Answer 6

Using “public” means that the routine can be called from outside of the program.

Question 7

A subroutine can’t exist by itself. What does it HAVE to be a part of?

Answer 7

A class

Question 8

What is a package?

Answer 8

A group of classes.

Question 9

To execute a program, you only need the compiled “ “ file, not the source code.

Answer 9

class

Question 10

When defining a variable, capitalizing every word except the first is referred to as what?

Answer 10

Camel case

Question 11

These names consist of several simple names separated by periods.

Answer 11

Compound names, also called qualified names.
Example: System.out.println

Question 12

An “ “ represents anything that refers to or computes a data value.

Answer 12

expression

Question 13

Name all of the primitive types. Hint: there are 8

Answer 13

1. byte - 16 bits
2. short
3. int - 32 bits
4. long - 64 bits
5. float
6. double
7. char
8. boolean

Question 14

What kind of numbers do float and double types hold?

Answer 14

real numbers

Question 15

What range of values can a byte type hold?

Answer 15

Anywhere from -128 to 127 which equals up to 256 integers.

Question 16

What range of values can a short type hold?

Answer 16

From -32,768 to 32,767 (16 bits)

Question 17

How many bytes of memory are float data types represented by?

Answer 17

Four bytes (chomp, chomp, chomp, chomp)

Question 18

How many bytes of memory does the char type occupy?

Answer 18

Two bytes (chomp, chomp)

Question 19

A char character is stored as a “” bit integer code number.

Answer 19

16

Question 20

A data value is stored in the computer as a sequence of what?

Answer 20

bits

Question 21

In a program, you represent constant values as “”.

Answer 21

literals (I literally did not know that)

Question 22

What is the escape character for a carriage return?

Answer 22

‘\r’

Question 23

What is the escape character for a linefeed?

Answer 23

‘\n’

Question 24

How can you express a number in an exponential form?

Answer 24

By using ‘e’
Example: ‘y = 1.3e12’
This means that 1.3 will be raised to the power of 12.

Question 25

Any numeric literal that contains a decimal point or exponential is a literal of type “ “.

Answer 25

double

Question 26

To make a literal of type float, you have to append what?

Answer 26

An ‘f’ or ‘F’ to the end of the float.
Example: ‘x = 1.2F;’

Question 27

In Java, a numeric literal that begins with a “” is interpreted as an octal number.

Answer 27

0 - zero

Question 28

Binary literals start with “” or “” and contain only the digits 0 and 1

Answer 28

0b or 0B

Question 29

A “” literal consists of \u followed by four hexadecimal digits.

Answer 29

Unicode (not to be confused with a Unicorn)

Question 30

A variable can be used in a program only if it has been?

Answer 30

declared

Question 31

What is the difference between the subroutine call System.out.print and the subroutine call System.out.println?

Answer 31

System.out.println adds a linefeed at the end while System.out.print does not.

Question 32

A “” provides a subroutine with information it needs to perform its task.

Answer 32

parameter

Question 33

Literals, variables, and function calls are considered “” expressions

Answer 33

simple

Question 34

How can you get Java to evaluate the expression you want over order or precedence?

Answer 34

By using parenthesis.
“(A + B) * C”

Question 35

Can you multiply a char character by a char character?

Answer 35

Yes! Char characters are Unicode which have a numerical value.

Question 36

The == operator checks whether two objects are stored in the same “ “, rather than whether they contain the same value.

Answer 36

memory location

Question 37

What does the following boolean expression do?
boolean test = true;
test = ! test;

Answer 37

Assigns a false value to the variable test. This is the boolean operator “not”

Question 38

The operators && and || are said to be “ “ versions of the boolean operators.

Answer 38

short-circuited

Question 39

What is this assignment called? “B = (short)A”

Answer 39

type cast