Download PrimitiveTypes

Primitive Types,
Strings, and Console I/O
 Variables, values, and Expressions
 The Class String
 Keyboard and Screen I/O
 Documentation and Style
Reading => Section 1.2
1
Variables and Values
 Variables are memory locations that store data such as numbers and letters.
 The data stored by a variable is called its value.
 The value is stored in the memory location.
 A variables value can be changed.
2
Variables and Values
public class Cows
{
public static void main (String[] args)
{
int barns, cowsPer, totalCows;
barns = 10;
Output:
cowsPer = 6;
If you have
6 cows per barn and
totalCows = barns * cowsPer;
10 barns, then
System.out.println ("If you have");
the total number of cows is 60
System.out.print(cowsPer);
System.out.println(" cows per barn and");
System.out.print(barns);
System.out.println(" barns, then");
System.out.print("the total number of cows is “);
System.out.println(totalCows);
}
}
3
Variables and Values
public class Cows
Output:
{
If you have
public static void main (String[] args)
6 cows per barn and
{
10 barns, then
int barns, cowsPer, totalCows;
the total number of cows is 60
barns = 10;
cowsPer = 6;
totalCows = barns * cowsPer;
System.out.println ("If you have");
System.out.println (cowsPer + " cows per barn and");
System.out.println (barns + " barns, then");
System.out.println ("the total number of cows is " + totalCows);
}
}
4
Variables and Values
 Variables:
barns
cowsPer
totalCows
 Assigning values:
barns = 10;
cowsPer = 6;
totalCows = barns * cowsPer;
 A variable must be declared before it is used.
 When you declare a variable, you provide its name and type.
int barns, cowsPer, totalCows;
 A variable’s type determines what kinds of values it can hold, e.g.,
integers, real numbers, characters.
5
Syntax and Examples
 Variable declaration syntax:
type variable_1, variable_2, …;
 Examples:
int styleChoice, numberOfChecks;
double balance, interestRate;
char jointOrIndividual;
 A variable is declared just before it is used or at the beginning of a
“block” enclosed in { }:
public static void main(String[] args)
{
/* declare variables here */
:
}
6
Types in Java
 In most programming languages, a type implies several things:
 A set of values
 A (hardware) representation for those values
 A set of operations on those values
 Example - type int:
 Values – integers in the range -2147483648 to 2147483647
 Representation – 4 bytes, binary, “two’s complement”
 Operations – addition (+), subtraction (-), multiplication (*), division (/), etc.
 Two kinds of types:
 Primitive types
 Class types
7
Types in Java
 A primitive type:
 values are “simple,” non-decomposable values such as an individual number
or individual character
 int, double, char
 A class type:
 values are “complex” objects
 a class of objects has both data and methods
 ‘November 10, 1989’ is a value of class type date (non-Java)
 “BIG bad John.” is a value of class type String
8
Java Identifiers
 An identifier is a name given to something in a program:
 a variable, method, class, etc.
 created by the programmer, generally
 Identifiers may contain only:
 letters
 digits (0 through 9)
 the underscore character (_)
 and the dollar sign symbol ($) which has a special meaning
 the first character cannot be a digit.
9
Java Identifiers
 Legal Examples:
count
name
address
count1
count2
count3
x
y
z
i
j
k
myFavoriteHobby
My_Favorite_Hobby
 Illegal Examples:
1count
_name
7-11
netscape.com
util.*
10
Java Identifiers, cont.
 Identifiers can be arbitrarily long.
 Java is case sensitive i.e., stuff, Stuff, and STUFF are different
identifiers.
 Keywords or reserved words have special, predefined meanings:
abstract assert boolean break byte case catch char class const
continue default do double else enum extends false final finally
float for goto if implements import instanceof int interface long
native new null package private protected public return short
static strictfp super switch synchronized this throw throws
transient true try void volatile while
 Keywords cannot be used as identifiers
11
Naming Conventions
 A common recommendation is to choose names that are helpful, or
rather readable, such as count or speed, but not c or s.
 Sometimes short names are appropriate.
 Variables (of both class and primitive types):
 begin with a lowercase letters (e.g. myName, myBalance).
 multiword names are “punctuated” using uppercase letters.
 Class types:
 begin with an uppercase letter (e.g. String, Scanner).
 Primitive types:
 begin with a lowercase letter (e.g. int, float).
12
Primitive Types
 Four integer types:
 byte
 short
 int (most common)
 long
 Two floating-point types:
 float
 double (most common)
 One character type:
 char
 One boolean type:
 boolean
13
Primitive Types, cont.
14
Examples of Primitive Values
 Integer values:
0
-1
365
12000
 Floating-point values:
0.99
-22.8
3.14159 5.0
 Character values:
`a`
`A`
`#`
` `
 Boolean values:
true
false
15
Motivation for Primitive Types
 Why are there several different integer types?
 storage space
 operator efficiency
 More generally, why are there different types at all?
 reflects how people understand different kinds of data, e.g., letter vs.
numeric grades
 makes code more readable (which is a big deal)
 helps prevent programmer errors
16
Assignment Statements
 An assignment statement is used to assign a value to a variable:
int answer;
answer = 42;
 The “equal sign” is called the assignment operator.
 In the above example, the variable named answer is assigned a value
of 42, or more simply, answer is assigned 42.
17
Assignment Statements, cont.
 Assignment syntax:
variable = expression ;
where expression can be
 a literal or constant (such as a number),
 another variable, or
 an expression which combines variables and literals using operators
18
Assignment Examples
 Examples:
int amount;
int score, numberOfCards, handicap;
int eggsPerBasket;
char firstInitial;
:
score = 3;
firstInitial = ‘W’;
amount = score;
score = numberOfCards + handicap;
eggsPerBasket = eggsPerBasket - 2;
=> Some note that the last line looks weird in mathematics. Why?
19
Assignment Evaluation
 The expression on the right-hand side of the assignment operator (=) is
evaluated first.
 The result is used to set the value of the variable on the left-hand side of
the assignment operator.
score = numberOfCards + handicap;
eggsPerBasket = eggsPerBasket - 2;
 The distinction between the two steps is very important!
20
Simple Input
 Sometimes data is needed and obtained from the user at run time.
 Simple keyboard input requires:
import java.util.*;
or
import java.util.Scanner;
at the beginning of the file.
21
Simple Input, cont.
 A “Scanner” object must be initialized before inputting data:
Scanner keyboard = new Scanner(System.in);
 To input data:
eggsPerBasket = keyboard.nextInt();
which reads one int value from the keyboard and assigns it to the
variable eggsPerBasket.
22
Simple Input, cont.
import java.until.Scanner;
Output:
public class Cows
Enter the number of barns: 10
{
Enter the number of cows per barn: 6
public static void main (String[] args)
Total number of cows is: 60
{
int barns, cowsPer, totalCows;
Suppose two cows per barn escape!
Total number of cows is now: 40
Scanner kb = new Scanner(System.in);
System.out.print(“Enter the number of barns: ”);
barns = kb.nextInt();
System.out.pring(“Enter the number of cows per barn: ”);
cowsPer = kb.nextInt();
totalCows = barns * cowsPer;
System.out.println(“Total number of cows is: “ + totalCows);
System.out.println(“Suppose two cows per barn escape!”);
cowsPer = cowsPer – 2;
totalCows = barns * cowsPer;
System.out.println(“Total number of cows is now: “ + totalCows);
}
}
23
Command-Line Arguments
 Frequently input is provided to a program at the command-line.
public class UseArgument
{
public static void main(String[] args)
{
System.out.print(“Hi, ”);
System.out.print(args[0]);
System.out.println(“. How are you?”);
}
}
 Sample interaction:
% javac UseArgument.java
% java UseArgument Alice
Hi, Alice. How are you?
% java UseArgument Bob
Hi, Bob. How are you?
24
Command-Line Arguments
 Frequently multiple values are provided at the command-line.
public class Use3Arguments
{
public static void main(String[] args)
{
System.out.print(“The first word is ”);
System.out.print(args[0]);
System.out.print(“, the second is ”);
System.out.print(args[1]);
System.out.print(“, and the third is ”);
System.out.println(args[2]);
}
}
 Sample interaction:
% javac Use3Arguments.java
% java Use3Arguments dog cat cow
The first word is dog, the second is cat, and the third is cow
25
Command-Line Arguments
 Command-line arguments can be numeric.
public class IntOps {
public static void main(String[] args) {
int a = Integer.parseInt(args[0]);
// Notice the variable declaration
int b = Integer.parseInt(args[1]);
// Notice the comments…lol
int sum
= a + b;
int prod = a * b;
int quot = a / b;
int rem
= a % b;
System.out.println(a + " + " + b + " = " + sum);
System.out.println(a + " * " + b + " = " + prod);
System.out.println(a + " / " + b + " = " + quot);
System.out.println(a + " % " + b + " = " + rem);
}
}
 Sample interaction:
% javac IntOps.java
% java IntOps 1234 99
1234 + 99 = 1333
1234 * 99 = 122166
1234 / 99 = 12
1234 % 99 = 46
26
Literals
 Values such as 2, 3.7, or ’y’ are called constants or literals.
 Integer literals can be preceded by a + or - sign, but cannot contain
commas.
 Every integer literal is either of type int or type long.
 The type of an integer literal can be determined by…looking at it!
27
Integer Literal Type
 An integer literal is of type long if it is suffixed with an letter L or l;
otherwise it is of type int.
 note that capital L is preferred
 Integer literals of type long:
 2L
777L
 -372L
1996L
 2147483648l
0l
 Integer literals of type int:
 2
777
 -372
1996
 2147483648
0
28
Floating Point Literals
 Floating point literals:
 Can be preceded by a + or - sign, but cannot contain commas
 Can be specified in (a type of) scientific notation
 Examples:
 865000000.0 can also be written as 8.65e8
 0.000483 can also be written as 4.83e-4
 The number in front of the “e” does not need to contain a decimal point,
e.g. 4e-4
29
Floating Point Literal Type
 Every floating point literal is either of type float or type double.
 The type of a floating point literal can be determined by…looking at it!
 An floating point literal is of type float if it is suffixed with an letter F or f;
otherwise it is of type double.
 Floating point literals of type float:
 2.5F
 8.65e8f
0.0f
 3f
+35.4f
 -16F
-16.0F
4e-4F
30
Assignment Compatibilities
 Java is said to be strongly typed, which means that there are limitations on
mixing variables and values in expressions and assignments.
 What is the type of the LHS and RHS for each statement?
int x = 0;
long y = 0;
float z = 0.0f;
int w;
w
x
x
y
z
y
=
=
=
=
=
=
x;
y;
z;
z;
3.6;
25;
//
//
//
//
//
//
legal; what does it do?
illegal
illegal
illegal
illegal (3.6 is of type double)
legal, but…why?
31
Assignment Compatibilities
 Sometimes automatic conversions between types do take place:
short s;
int x;
s = 83;
x = s;
double doubleVariable;
int intVariable;
intVariable = 7;
doubleVariable = intVariable;
32
Assignment Compatibilities, cont.
 In general, a value (or expression) of one numeric type can be assigned
to a variable of any type further to the right, as follows:
byte --> short --> int --> long --> float --> double
but not to a variable of any type further to the left.
 Makes sense intuitively because, for example, any legal byte value is a
legal short value.
 On the other hand, many legal short values are not legal byte values.
33
Assignment Compatibilities, cont.
 Example – all of the following are legal, and will compile:
byte b = 0;
short s;
int i;
long l;
float f;
double d;
s = b;
i = b;
l = i;
f = l;
// This one is interesting, why?
d = f;
b = 10;
34
Assignment Compatibilities, cont.
 Example – NONE (except the first) of the following will compile:
byte b;
short s;
int i;
long l;
float f;
double d;
d = 1.0;
// This one compiles
f = d;
l = f;
i = l;
s = i;
b = s;
35
Type Casting
 A type cast creates a value in a new type from an original type.
 A type cast can be used to force an assignment when otherwise it would
be illegal (thereby over-riding the compiler, in a sense).
 Example:
double distance;
distance = 9.0;
int points;
points = distance;
// illegal
points = (int)distance;
// legal
36
Type Casting, cont.
 The value of (int)distance is 9, but the value of distance, both
before and after the cast, is 9.0.
 The type of distance does NOT change and remains double.
 What happens if distance contains 9.7?
 Any value right of the decimal point is truncated (as oppossed to rounded).
37
Type Casting, cont.
 A cast can be performed from any primitive type to any other primitive
type, however…
 Remember to “cast with care,” because the results can be unpredictable.
int x;
long z = ?;
// ? Could be a computation or input
x = (int)z;
38
Characters as Integers
 Like everything else, each character is represented by a binary sequence.
 The binary sequence corresponding to a character is a positive integer.
 Which integer corresponds to each character is dictated by a standardized
character encoding.
 Each character is assigned a unique integer code
 The codes are different for upper and lower case letters, e.g., 97 may be the
integer value for ‘a’ and 65 for ‘A’
 Some characters are printable, others are not
 Why should different computers and languages use the same code?
 ASCII and Unicode are the most common character codes.
39
Unicode Character Set
 Most programming languages use the ASCII character encoding.

American Standard Code for Information Interchange (ASCII)

(only) encodes characters from the north American keyboard

uses one byte of storage
 Java uses the Unicode character encoding.
 The Unicode character set:
 uses two bytes of storage
 includes many international character sets (in contrast to ASCII)
 codes characters from the North American keyboard the same way that
ASCII does
Hey, lets google ASCII!!!!
40
Assigning a char to an int
 A value of type char can be assigned to a variable of type int to obtain
its Unicode value.
 Example:
char answer = ’y’;
System.out.println(answer);
System.out.println((int)answer);
>y
>121
 See the program at:
http://www.cs.fit.edu/~pbernhar/teaching/cse1001/charTest
41
Initializing Variables
 A variable that has been declared, but not yet given a value is said to be
uninitialized.
int x, y, z;
x = y;
x = z + 1;
 Some languages automatically initialize a variable when it’s declared,
other languages don’t.
 Others (Java) initialize in some circumstances, but not in others.
 Variables declared to be of a primitive type are NOT automatically initialized.
 In other cases Java will initialize variables; this will be discussed later.
42
Initializing Variables
 Some languages report an error when a variable is used prior to
initialization by the program.
 Sometimes at compile time, other times at run-time.
 Some languages won’t report an error, and will even let you use an
uninitialized variable.
 In such cases the initial value of the variable is arbitrary!
 The program might appear to run correctly sometimes, but give errors on
others.
 Java:
 The compiler will (try) to catch uninitialized variables.
=> Always make sure your variables are initialized prior to use!
43
Initializing Variables, cont.
 In Java, a variable can be assigned an initial value in it’s declaration.
 Examples:
int count = 0;
char grade = ’A’;
// default is an A
 Syntax:
type variable1 = expression1, variable2 = expression2, …;
44
Arithmetic Operations
 Arithmetic expressions:
 Formed using the +, -, *, / and % operators
 Operators have operands, which are literals, variables or sub-expressions.
 Expressions with two or more operators can be viewed as a series of
steps, each involving only two operands.
 The result of one step produces an operand which is used in the next step.
 Java is left-associative.
 Most of the basic rules of precedence apply.
 Example:
int x = 0, y = 50, z = 20;
double balance = 50.25, rate = 0.05;
x = x + y + z;
balance = balance + balance * rate;
balance = (balance + balance) * rate;
45
Expression Type
 An arithmetic expression can have operands of different numeric types.
 x + (y * z) / w
 Note that this does not contradict our rules for assignment.
 Every arithmetic expression has a (resulting) type.
 k = x + (y * z) / w;
// Does this compile?
 Given an arithmetic expression:
 If any operand in the expression is of type double, then the expression has
type double.
 Otherwise, if any operand in the expression is of type float, then the
expression has type float.
 Otherwise, if any operand in the expression is of type long, then the
expression has type long.
 Otherwise the expression has type int.
46
Expression Type, cont.
 Example:
int hoursWorked
= 40;
double payRate
= 8.25;
double totalPay;
Then the expression in the assignment:
totalPay = hoursWorked * payRate
is a double with a value of 500.0.
47
Operators with integer
and floating point numbers
 See the program:
 http://www.cs.fit.edu/~pbernhar/teaching/cse1001/expressions
 http://www.cs.fit.edu/~pbernhar/teaching/cse1001/integralConversion
48
The Division Operator
 The division operator (/) behaves as expected.
 If one of the operands is a floating-point type then the result is of the
same floating point type.
 9.0 / 2 = 4.5
 9 / 2.0 = 4.5
 If both operands are integer types then the result is truncated, not
rounded.


9/2 = 4

99 / 100 = 0
Note that the typing rules previously presented still apply!
49
The mod Operator
 The mod (%) operator is used with operands of integer type to obtain the
remainder after integer division.
 14 divided by 4 is 3 with a remainder of 2.
 Hence, 14 % 4 is equal to 2.
 The mod operator has many uses, including determining:
 If an integer is odd or even (x % 2 = 0)
 If one integer is evenly divisible by another integer (a % b = 0)
 Frequently we want to map (a large number of) m “items,” number 1 through
m, into n>=2 buckets.
50
Example: Vending Machine
A really bad example, with 3 good lessons:
 Requirements
 Iterative enhancement (spiral vs waterfall)
 Testing
51
Example: Vending Machine
 Program Requirements:




The user enters an amount between 1 cent and 99 cents.
The program determines a combination of coins equal to that amount.
For example, 55 cents can be two quarters and one nickel.
Largest denominations are given preference.
=> What are “requirements” anyway?
 Sample dialog:
Enter a whole number from 1 to 99.
The machine will determine a combination of coins.
87
87 cents in coins:
3 quarters
1 dime
0 nickels
2 pennies
52
Example, cont.
 Algorithm (version #1, in pseudo-code):
1. Input the amount from the user.
2. Find the maximum number of quarters in the amount.
3. Subtract the value of the quarters from the amount.
4. Repeat the last two steps for dimes, nickels, and pennies.
5. Print the amount and the quantities of each coin.
 Program Variables Needed:
int amount, quarters, dimes, nickels, pennies;
53
Example, cont.
 Interpreted literally, the algorithm leaves some details:
 The user must be prompted for the amount.
 The original amount is changed (and hence lost) by the intermediate steps.
 So we add an additional variable:
int amount, originalAmount, quarters, dimes,
nickles, pennies;
and update the algorithm.
54
Example, cont.
 Algorithm (version #2):

1.
Prompt the user for the amount.
2.
Input the amount.
3.
Make a copy of the amount.
4.
Find the maximum number of quarters in the amount.
5.
Subtract the value of the quarters from the amount.
6.
Repeat the last two steps for dimes, nickels, and pennies.
7.
Print the original amount and the quantities of each coin.
Typically pseudo-code is iteratively embellished or enhanced.
55
Example, cont.
 How do we determine the number of quarters in an amount?
 There are 2 quarters in 55 cents, but there are also 2 quarters in 65 cents.
 That’s because 55 / 25 = 2 and 65 / 25 = 2.
 How do we determine the remaining amount?
 Using the mod operator:
55 % 25 = 5 and 65 % 25 = 15
 Similarly for dimes, nickels and pennies
 Pennies are simply amount % 5.
56
Example, cont.
57
Testing the Program
 The program should be tested with several different amounts.
 Test with values that give zero values for each possible coin
denomination.
 Test with amounts close to:
 “Extreme” or “boundary condition” values such as 0, 1, 98 and 99.
 Coin denominations such as 24, 25, and 26.
58
Increment (and Decrement) Operators
 Used to increase (or decrease) the value of a variable by 1.
 count = count +1
 count = count -1
 The increment and decrement operations are easy to use, and
important to recognize.
 The increment operator:
 count++
 ++count
 The decrement operator:
 count- --count
59
Increment (and Decrement) Operators
 “Mostly” equivalent operations:
count++;
++count;
count = count + 1;
count--;
--count;
count = count - 1;
 Unlike the assignment versions, however, the increment and decrement
operators are operators and have a resulting value…huh?
60
Increment (and Decrement)
Operators in Expressions
 After executing:
int m = 4;
int result = 3 * (++m);
result has a value of 15 and m has a value of 5
 After executing:
int m = 4;
int result = 3 * (m++);
result has a value of 12 and m has a value of 5
61
Increment and Decrement Operator, Cont.
 Common code:
int n = 3;
int m = 4;
int result;
 What will be the value of m and result after each of these executes?
(a) result = n * ++m;
(b) result = n * m++;
(c) result = n * --m;
(d) result = n * m--;
62
The Class String
 As we already have seen, a String is a sequence of characters.
 We’ve used constants, or rather, literals of type String:
“Enter a whole number from 1 to 99.”
“Number of quarters:”
“I will output a combination of coins”
63
Declaring and Printing Strings
 Variables of type String can be declared and Initialized:
String greeting;
greeting = “Hello!”;
 Equivalent to the above:
String greeting = “Hello!”;
String greeting = new String(“Hello!”);
 Printing:
System.out.println(greeting);
64
Inputting Strings
 Variables of type String can be input:
String Word;
System.out.print(“Enter a word:”);
Word = keyboard.next();
System.out.print(“The word entered was: “ + Word);
65
Concatenation of Strings
 Two strings can be concatenated using the + operator:
String s1 = “Hello”;
String s2 = “Smith”;
String s3;
s3 = s1 + “ officer ”;
s3 = s3 + s2;
System.out.println(s3);
 Any number of strings can be concatenated using the + operator.
66
Concatenating Strings and Integers
 Strings can be concatenated with other types:
String solution;
solution = “The temperature is “ + 72;
System.out.println (solution);
 Output:
The temperature is 72
67
Classes
 Recall that Java has primitive types and class types:
 primitive types
 class types
 Primitive types have:
 simple, “atomic,” non-decomposable values
 operations (built-in, usually a symbol such as *, +, or -)
 used to declare variables
 Class types have:
 complex values, with structure
 methods (some built-in, others user-defined, usually a word)
 used to declare “objects”
68
The Class String
 String is a class type, which means it has methods.
 The length() method returns an int, which is the number of
characters in a particular String object.
String solution = “dog”;
int count = solution.length();
 You can use a call to method length() anywhere an int can be used.
System.out.println(solution.length());
int X = 10;
X = X * solution.length() + 3;
69
Positions in a String
 Each character in a String has its own position.
 Positions are numbered starting at 0.
 ‘J’ in “Java is fun.” is in position 0
 ‘f’ in “Java is fun.” is in position 8
 The position of a character is also referred to as its index.
70
Positions in a String, cont.
71
Indexing Characters within a String
using Methods
 charAt(position)
 returns the char at the specified position

Example:
String greeting = "Hi, there!";
char ch1 = greeting.charAt(0);
// Stores ‘H’ in ch1
char ch2 = greeting.charAt(2);
// Stores ‘,’ in ch2
 substring(start, end)
 returns the string from start up to, but not including, end
String myWord;
myWord = greeting.substring(4,7) // Stores the in myWord
72
String Methods
 There are many Java String methods.
 See the Java on-line documentation for more details!
73
Escape Characters
 How would you print the following?
“Java” refers to a language.
 The following don’t work:
System.out.println(“Java refers to a language.”);
System.out.println(““Java” refers to a language.”);
 The compiler needs to be told that the quotation marks (“) do not signal
the start or end of a string, but instead are to be printed.
System.out.println(“\”Java\” refers to a language.”);
74
Escape Characters
 “Escape sequences” are used to print “problematic” characters.
\”
Double quote
\’
Single quote
\\
Backslash
\n
Newline (beginning of next line)
\r
Carriage return (beginning of current line)
\t
tab
 Each escape sequence is a single character even though it is written
with two symbols.
75
Examples
 Examples:
System.out.println(“abc\\def”);
=>
abc\def
System.out.println(“new\nline”);
=>
new
line
char singleQuote = ‘\’’;
System.out.println(singleQuote);
=>
76
‘
Example of Class String
77
Examples
Modify the previous program so that it prompts the user for a sentence and
two words. The program will modify the sentence by replacing the first
occurrence of the first word with the second word.
Enter a sentence: Gosh sunny, it sure is sunny today.
Enter a word: sunny
Enter another word: bob
Resulting sentence: Gosh bob, it sure is sunny today.
78
Number Constants
Decimal
0000
0001
0002
0003
0004
0005
0006
0007
0008
0009
0010
0011
0012
0013
0014
0015
0016
0017
0018
0019
0020
0021
0022
0023
0024
0025
0026
0027
0028
0029
0030
0031
0032
Binary
000000
000001
000010
000011
000100
000101
000110
000111
001000
001001
001010
001011
001100
001101
001110
001111
010000
010001
010010
010011
010100
010101
010110
010111
011000
011001
011010
011011
011100
011101
011110
011111
100000
Octal
0000
0001
0002
0003
0004
0005
0006
0007
0010
0011
0012
0013
0014
0015
0016
0017
0020
0021
0022
0023
0024
0025
0026
0027
0030
0031
0032
0033
0034
0035
0036
0037
0040
Hexidecimal
0000
0001
0002
0003
0004
0005
0006
0007
0008
0009
000A
000B
000C
000D
000E
000F
0010
0011
0012
0013
0014
0015
0016
0017
0018
0019
001A
001B
001C
001D
001E
001F
0020
79