This presentation will cover all you need to know about mobile and application device security.
With an introduction, threats, applications, security, and useful tips for people who need to know
So, let's get started. If you enjoy this and find the information beneficial, please like and share it with your friends.
Information and network security 13 playfair cipherVaibhav Khanna
The Playfair cipher was the first practical digraph substitution cipher. The scheme was invented in 1854 by Charles Wheatstone but was named after Lord Playfair who promoted the use of the cipher. In playfair cipher unlike traditional cipher we encrypt a pair of alphabets(digraphs) instead of a single alphabet
This presentation will cover all you need to know about mobile and application device security.
With an introduction, threats, applications, security, and useful tips for people who need to know
So, let's get started. If you enjoy this and find the information beneficial, please like and share it with your friends.
Information and network security 13 playfair cipherVaibhav Khanna
The Playfair cipher was the first practical digraph substitution cipher. The scheme was invented in 1854 by Charles Wheatstone but was named after Lord Playfair who promoted the use of the cipher. In playfair cipher unlike traditional cipher we encrypt a pair of alphabets(digraphs) instead of a single alphabet
Slides for a college course at City College San Francisco. Based on "The Shellcoder's Handbook: Discovering and Exploiting Security Holes ", by Chris Anley, John Heasman, Felix Lindner, Gerardo Richarte; ASIN: B004P5O38Q.
Instructor: Sam Bowne
Class website: https://samsclass.info/127/127_S17.shtml
WAP Model- Mobile Location based services -WAP Gateway –WAP protocols – WAP
user agent profile- caching model-wireless bearers for WAP - WML – W MLScripts - WTA
- iMode- SyncML.
This produced by straight forward compiling algorithms made to run faster or less space or both. This improvement is achieved by program transformations that are traditionally called optimizations.compiler that apply-code improving transformation are called optimizing compilers.
SUN Network File system - Design, Implementation and Experience aniadkar
Overview of SUN Network File system and its design, architecture and implementation along with changes in NFS v3 and NFS v4
Presented by – Aniruddh Adkar
CSE 710 Parallel and Distributed File Systems ( Spring 2016 )
SUNY, University at Buffalo
Remote Procedure Call in Distributed SystemPoojaBele1
Presentation to give description about the remote procedure call in distributed systems
Presentation covers some points on remote procedure call in distributed systems
Java Foundations: Data Types and Type ConversionSvetlin Nakov
Learn how to use data types and variables in Java, how variables are stored in the memory and how to convert from one data type to another.
Watch the video lesson and access the hands-on exercises here: https://softuni.org/code-lessons/java-foundations-certification-data-types-and-variables
Slides for a college course at City College San Francisco. Based on "The Shellcoder's Handbook: Discovering and Exploiting Security Holes ", by Chris Anley, John Heasman, Felix Lindner, Gerardo Richarte; ASIN: B004P5O38Q.
Instructor: Sam Bowne
Class website: https://samsclass.info/127/127_S17.shtml
WAP Model- Mobile Location based services -WAP Gateway –WAP protocols – WAP
user agent profile- caching model-wireless bearers for WAP - WML – W MLScripts - WTA
- iMode- SyncML.
This produced by straight forward compiling algorithms made to run faster or less space or both. This improvement is achieved by program transformations that are traditionally called optimizations.compiler that apply-code improving transformation are called optimizing compilers.
SUN Network File system - Design, Implementation and Experience aniadkar
Overview of SUN Network File system and its design, architecture and implementation along with changes in NFS v3 and NFS v4
Presented by – Aniruddh Adkar
CSE 710 Parallel and Distributed File Systems ( Spring 2016 )
SUNY, University at Buffalo
Remote Procedure Call in Distributed SystemPoojaBele1
Presentation to give description about the remote procedure call in distributed systems
Presentation covers some points on remote procedure call in distributed systems
Java Foundations: Data Types and Type ConversionSvetlin Nakov
Learn how to use data types and variables in Java, how variables are stored in the memory and how to convert from one data type to another.
Watch the video lesson and access the hands-on exercises here: https://softuni.org/code-lessons/java-foundations-certification-data-types-and-variables
To write Java programs to perform simple calculations (§2.2).
To obtain input from the console using the Scanner class (§2.3).
To use identifiers to name variables, constants, methods, and classes (§2.4).
To use variables to store data (§§2.5-2.6).
To program with assignment statements and assignment expressions (§2.6).
To use constants to store permanent data (§2.7).
To declare Java primitive data types: byte, short, int, long, float, double, and char (§§2.8.1).
To use Java operators to write numeric expressions (§§2.8.2–2.8.3).
To display current time (§2.9).
To use short hand operators (§2.10).
To cast value of one type to another type (§2.11).
To compute loan payment (§2.12).
To represent characters using the char type (§2.13).
To compute monetary changes (§2.14).
To represent a string using the String type (§2.15).
To become familiar with Java documentation, programming style, and naming conventions (§2.16).
To distinguish syntax errors, runtime errors, and logic errors and debug errors (§2.17).
(GUI) To obtain input using the JOptionPane input dialog boxes (§2.18).
In this chapter we will get familiar with primitive types and variables in Java – what they are and how to work with them. First we will consider the data types – integer types, real types with floating-point, Boolean, character, string and object type. We will continue with the variables, with their characteristics, how to declare them, how they are assigned a value and what is variable initialization.
MATLAB DOCUMENTATION ON SOME OF THE MODULES
A.Generate videos in which a skeleton of a person doing the following Gestures.
1.Tilting his head to right and left
2.Tilting his hand to right and left
3.Walking
in matlab.
B. Write a MATLAB program that converts a decimal number to Roman number and vice versa.
C.Using EZ plot & anonymous functions plot the following:
· Y=Sqrt(X)
· Y= X^2
· Y=e^(-XY)
D.Take your picture and
· Show R, G, B channels along with RGB Image in same figure using sub figure.
· Convert into HSV( Hue, saturation and value) and show the H,S,V channels along with HSV image
E.Record your name pronounced by yourself. Try to display the signal(name) in a plot vs Time, using matlab.
F.Write a script to open a new figure and plot five circles, all centered at the origin and with increasing radii. Set the line width for each circle to something thick (at least 2 points), and use the colors from a 5-color jet colormap (jet).
G. NEWTON RAPHSON AND SECANT METHOD
H.Write any one of the program to do following things using file concept.
1.Create or Open a file
2. Read data from the file and write data to another file
3. Append some text to already existed file
4. Close the file
I.Write a function to perform following set operations
1.Union of A and B
2. Intersection of A and B
3. Complement of A and B
(Assume A= {1, 2, 3, 4, 5, 6}, B= {2, 4, 6})
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
2. 2
Motivations
In the preceding chapter, you learned
how to create, compile, and run a Java
program.
you will learn how to solve practical problems
programmatically.
Through these problems, you will learn Java
primitive data types and related subjects,
such as variables, constants, data types,
operators, expressions, and input and output.
3. 3
Introducing Programming with an Example
Listing 2.1 Computing the Area of a Circle
public class ComputeArea {
public static void main(String[] args) {
double radius; // Declare radius
double area; // Declare area
radius = 20; // Assign a radius
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println
("The area for the circle of radius " +
radius + " is " + area);
}
}
4. 4
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
no valueradius
allocate memory
for radius
animation
5. 5
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
no valueradius
memory
no valuearea
allocate memory
for area
animation
6. 6
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20radius
no valuearea
assign 20 to radius
animation
7. 7
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20radius
memory
1256.636area
compute area and assign
it to variable area
animation
8. 8
Trace a Program Execution
public class ComputeArea {
/** Main method */
public static void main(String[] args) {
double radius;
double area;
// Assign a radius
radius = 20;
// Compute area
area = radius * radius * 3.14159;
// Display results
System.out.println("The area for the circle of radius " +
radius + " is " + area);
}
}
20radius
memory
1256.636area
print a message to the
console
animation
9. 9
Identifiers
An identifier is a sequence of characters that consist of
letters, digits, underscores (_), and dollar signs ($).
An identifier must start with a letter, an underscore (_),
or a dollar sign ($). It cannot start with a digit.
An identifier cannot be a reserved word. (See Appendix A,
“Java Keywords,” for a list of reserved words).
An identifier cannot be true, false, or null.
An identifier can be of any length.
Java is case sensitive
Upper case letters are the same as lower case letters
Examples
Name is not the same as name
10. 10
Variables
The area is 3.14159 for radius 1.0
The area is 12.56636 for radius 2.0
public class DisplayRadius {
public static void main(String[]args) {
double radius; //Declare variable radius
double area; //Declare variable area
// Compute the first area
radius = 1.0; //assign value to variable radius
area = radius * radius * 3.14159; //compute value of area
System.out.println("The area is " + area +
" for radius " + radius);
// Compute the second area
radius = 2.0; //assign value to variable radius
area = radius * radius * 3.14159; //compute value of area
System.out.println("The area is " + area +
" for radius "+radius);
}
}
11. 11
Declaring Variables
int x; // Declare x to be an
// integer variable;
double radius; // Declare radius to
// be a double variable;
char a; // Declare a to be a
// character variable;
• Declarations are used to
• tell the compiler how much memory space is needed
for the value that will be assigned to the variable
• tell the compiler the type of data that will be
referenced by that variable
12. 12
Assignment Statements
x = 1; // Assign 1 to x;
radius = 1.0; // Assign 1.0 to radius;
a = ‘D'; // Assign ‘D' to a;
• Assignment statements
• Assign a value to the variable
• That value is stored in the memory location
associated with that variable
13. 13
Declaring and Initializing in One Step
int x = 1;
double d = 1.4;
• In Jave, you can declare a variable and store a value in
that variable in one statement
• It is usually a good idea to initialize the variable when it is
declared
14. 14
Constants
Constant
Once a value is assigned it cannot be changed
final is the keyword used to declare a variable a
constant
Format
final datatype CONSTANTNAME = VALUE;
Examples
final double PI = 3.14159;
final int SIZE = 3;
Note
Convention is to use all upper case letters for the
name of the constant variable
15. 15
Numerical Data Types
Name Range Storage Size
byte –27 (-128) to 27–1 (127) 8-bit signed
short –215 (-32768) to 215–1 (32767) 16-bit signed
int –231 (-2147483648) to 231–1 (2147483647) 32-bit signed
long –263 to 263–1 64-bit signed
(i.e., -9223372036854775808
to 9223372036854775807)
float Negative range: 32-bit IEEE 754
-3.4028235E+38 to -1.4E-45
Positive range:
1.4E-45 to 3.4028235E+38
double Negative range: 64-bit IEEE 754
-1.7976931348623157E+308 to
-4.9E-324
Positive range:
4.9E-324 to 1.7976931348623157E+308
16. 16
Numeric Operators
Name Meaning Example Result
+ Addition 34 + 1 35
- Subtraction 34.0 – 0.1 33.9
* Multiplication 300 * 30 9000
/ Division 1.0 / 2.0 0.5
% Remainder 20 % 3 2
17. 17
Integer Division
+, -, *, /, and %
5 / 2 yields an integer 2.
5.0 / 2 yields a double value 2.5
5 % 2 yields 1 (the remainder of the division)
18. 18
Remainder Operator
Remainder is very useful in programming.
For example
an even number % 2 is always 0
an odd number % 2 is always 1.
So you can use this property to determine whether a
number is even or odd.
Suppose today is Saturday and you and your friends are
going to meet in 10 days. What day is in 10 days? You
can find that day is Tuesday using the following
expression:
Saturday is the 6th
day in a week
A week has 7 days
After 10 days
The 2nd
day in a week is Tuesday
(6 + 10) % 7 is 2
19. 19
Problem: Displaying Time
Write a program that obtains hours and
minutes from seconds.
public class DisplayTime {
public static void main(String[] args) {
int seconds = 500;
int minutes = seconds / 60;
int remainingSeconds = seconds % 60;
System.out.println(seconds + " seconds is " + minutes +
" minutes and " + remainingSeconds + " seconds");
}
}
500 seconds is 8 minutes and 20 seconds
20. 20
NOTE
Calculations involving floating-point numbers are
approximated because these numbers are not stored
with complete accuracy. For example,
System.out.println(1.0 - 0.1 - 0.1 - 0.1 - 0.1 - 0.1);
displays 0.5000000000000001, not 0.5, and
System.out.println(1.0 - 0.9);
displays 0.09999999999999998, not 0.1.
Integers are stored precisely. Therefore, calculations
with integers yield a precise integer result.
21. 21
Number Literals
A literal is a constant value that appears directly
in the program.
For example, 34, 1,000,000, and 5.0 are literals in
the following statements:
int i = 34;
long x = 1000000;
double d = 5.0;
22. 22
Integer Literals
An integer literal can be assigned to an integer
variable as long as it can fit into the variable.
A compilation error would occur if the literal were too
large for the variable to hold.
For example, the statement byte b = 1000 would cause
a compilation error, because 1000 cannot be stored in a
variable of the byte type.
An integer literal is assumed to be of the int type,
whose value is between
-231
(-2147483648) to 231
–1 (2147483647).
To denote an integer literal of the long type, append it
with the letter L or l.
L is preferred because l (lowercase L) can easily be
confused with 1 (the digit one).
23. 23
Floating-Point Literals
Floating-point literals are written with a decimal point.
By default, a floating-point literal is treated as a double
type value.
For example, 5.0 is considered a double value, not a
float value.
You can make a number a float by appending the letter
f or F
You make a number a double by appending the letter d
or D.
For example, you can use 100.2f or 100.2F for a float
number, and 100.2d or 100.2D for a double number.
24. 24
Scientific Notation
Floating-point literals can also be specified in
scientific notation
For example, 1.23456e+2, same as 1.23456e2, is
equivalent to 123.456, and 1.23456e-2 is equivalent
to 0.0123456.
E (or e) represents an exponent and it can be
either in lowercase or uppercase.
26. 26
How to Evaluate an Expression
Though Java has its own way to evaluate an
expression behind the scene, the result of a Java
expression and its corresponding arithmetic
expression are the same. Therefore, you can safely
apply the arithmetic rule for evaluating a Java
expression. 3 + 4 * 4 + 5 * (4 + 3) - 1
3 + 4 * 4 + 5 * 7 – 1
3 + 16 + 5 * 7 – 1
3 + 16 + 35 – 1
19 + 35 – 1
54 - 1
53
(1) inside parentheses first
(2) multiplication
(3) multiplication
(4) addition
(6) subtraction
(5) addition
Appendix C, page 690, has a
chart of operator precedence.
27. 27
Problem: Converting Temperatures
Write a program that converts a Fahrenheit
degree to Celsius using the formula:
)32)((9
5
−= fahrenheitcelsius
public class FahrenheitToCelsius {
public static void main(String[] args) {
double fahrenheit = 435; // Say 100;
double celsius = (5.0 / 9) * (fahrenheit - 32);
System.out.println("Fahrenheit " + fahrenheit +
" is " + celsius + " in Celsius");
}
}
Fahrenheit 435.0 is 223.88888888888889 in Celsius
28. 28
Shortcut Assignment Operators
Operator Example Equivalent
+= i += 8 i = i + 8
-= f -= 8.0 f = f - 8.0
*= i *= 8 i = i * 8
/= i /= 8 i = i / 8
%= i %= 8 i = i % 8
29. 29
Increment and Decrement Operators
Operator Name Description
++var preincrement The expression (++var) increments var by 1 and evaluates
to the new value in var after the increment.
var++ postincrement The expression (var++) evaluates to the original value
in var and increments var by 1.
--var predecrement The expression (--var) decrements var by 1 and evaluates
to the new value in var after the decrement.
var-- postdecrement The expression (var--) evaluates to the original value
in var and decrements var by 1.
++var and --var: performs the arithmetic operation first than uses the value.
var++ and var– uses the value first than performs the arithmetic operation.
30. 30
Increment and Decrement Operators, cont.
int i = 10;
int newNum = 10 * i++; int newNum = 10 * i;
i = i + 1;
Same effect as
int i = 10;
int newNum = 10 * (++i); i = i + 1;
int newNum = 10 * i;
Same effect as
newNum will have the value 100, i will have the value 11
newNum will have the value 110, i will have the value 11
31. 31
Increment and Decrement Operators, cont.
Using increment and decrement operators makes
expressions short, but it also makes them complex and
difficult to read.
Avoid using these operators in expressions that modify
multiple variables, or the same variable for multiple
times such as this: int k = ++i + i.
32. 32
Assignment Expressions and Assignment Statements
Prior to Java 2, all the expressions could be used as
statements. Since Java 2, only the following types of
expressions can be statements:
variable op= expression; // Where op is +, -, *, /, or %
++variable;
variable++;
--variable;
variable--;
• Expressions perform operations on data and move data around.
• All statements except blocks are terminated by a semicolon. Blocks are
denoted by open and close curly braces.
33. 33
Numeric Type Conversion
Consider the following statements:
byte i = 100;
long k = i * 3 + 4;
double d = i * 3.1 + k / 2;
• Some of the statements have mixed types
• byte types are mixed with long types
• byte and long types are mixed with double type
byte type
long type
34. 34
Conversion Rules
When performing a binary operation involving two
operands of different types, Java automatically converts
the operand based on the following rules:
1. If one of the operands is double, the other is converted into
double.
2. Otherwise, if one of the operands is float, the other is
converted into float.
3. Otherwise, if one of the operands is long, the other is
converted into long.
4. Otherwise, both operands are converted into int.
35. 35
Type Casting
Implicit casting
double d = 3; (type widening)
Explicit casting
int i = (int)3.0; (type narrowing)
int i = (int)3.9; (Fraction part is truncated)
What is wrong? int x = 5 / 2.0;
converts the 5 to 5.0, performs division to get 2.5 then tries to
store a double in an int, but it won’t fit. You will get a compile
error.
byte, short, int, long, float, double
range increases
8-bits 16-bits 32-bits 64-bits 32-bits 64-bits
Will store 3.000000000
Will store 3
36. 36
Problem: Keeping Two Digits After Decimal Points
Write a program that displays the sales tax with
two digits after the decimal point.
public class SalesTax {
public static void main(String[] args) {
double purchaseAmount = 197.55;
double tax = purchaseAmount * 0.06;
System.out.println("Sales tax is $" + tax);
System.out.println("Sales tax is $" +
(int)(tax * 100) / 100.0);
}
}
Sales tax is $11.853
Sales tax is $11.85
37. 37
Character Data Type
char letter = 'A'; (ASCII)
char numChar = '4'; (ASCII)
char letter = 'u0041'; (Unicode)
char numChar = 'u0034'; (Unicode)
Four hexadecimal digits.
NOTE: The increment and decrement operators can also be used
on char variables to get the next or preceding Unicode character.
For example, the following statements display character b.
char ch = 'a';
System.out.println(++ch);
38. 38
Unicode Format
Java characters use Unicode, a 16-bit encoding scheme
established by the Unicode Consortium to support the
interchange, processing, and display of written texts in
the world’s diverse languages. Unicode takes two bytes,
preceded by u, expressed in four hexadecimal numbers
that run from 'u0000' to 'uFFFF'. So, Unicode can
represent 65535 + 1 characters.
Unicode u03b1 u03b2 u03b3 for three Greek
letters
39. 39
Problem: Displaying Unicodes
Write a program that displays two Chinese
characters and three Greek letters.
import javax.swing.JOptionPane;
public class DisplayUnicode {
public static void main(String[] args) {
JOptionPane.showMessageDialog(null,
"u6B22u8FCE u03b1 u03b2 u03b3",
"u6B22u8FCE Welcome",
JOptionPane.INFORMATION_MESSAGE);
}
}
40. 40
Escape Sequences for Special Characters
Description Escape Sequence Unicode
Backspace b u0008
Tab t u0009
Linefeed n u000A
Carriage return r u000D
Backslash u005C
Single Quote ' u0027
Double Quote " u0022
41. 41
Appendix B: ASCII Character Set
ASCII Character Set is a subset of the Unicode from u0000 to u007f
1
2
42. 42
ASCII Character Set, cont.
ASCII Character Set is a subset of the Unicode from u0000 to u007f
1
2
43. 43
Casting between char and Numeric Types
int i = 'a'; // Same as int i = (int)'a';
char c = 97; // Same as char c = (char)97;
44. 44
The String Type
The char type only represents one character. To represent a string
of characters, use the data type called String. For example,
String message = "Welcome to Java";
• String is actually a predefined class in the Java library just like the
System class and JOptionPane class.
• The String type is not a primitive type. It is known as a reference
type.
• Any Java class can be used as a reference type for a variable.
• Reference data types will be thoroughly discussed in Chapter 7,
“Objects and Classes.”
• For the time being, you just need to know how to declare a String
variable, how to assign a string to the variable, and how to
concatenate strings.
45. 45
String Concatenation
// Three strings are concatenated
String message = "Welcome " + "to " + "Java";
// String Chapter is concatenated with number 2
String s = "Chapter" + 2; // s becomes Chapter2
// String Supplement is concatenated with character B
String s1 = "Supplement" + 'B'; // s becomes SupplementB
Create a String type named message and
store “Welcome to Java” at that location
Create a String type named s and store
“Chapter2” at that location
Create a String type named s1 and store
“SupplementB” at that location
46. 46
String Concatenation (cont.)
// add to message
String message = "Welcome " + "to " + "Java";
Message = message + “! Good luck!!”
Create a String type named message and store “Welcome to Java” at that
location. Then add “! Good luck!!” to message and now “Welcome to Jave! Good
luck!!” is stored at location message.
47. 47
Obtaining Input
This book provides two ways of obtaining input.
1. Using JOptionPane input dialogs (§2.11)
Inputs from a GUI window.
2. Using the JDK 1.5 Scanner class (§2.16)
Inputs from DOS window or lower pane in
Eclipse workspace.
48. 48
Getting Input Using Scanner
1. Need to import Scanner
import java.util.Scanner;
2. Create a Scanner object
Scanner scanner = new Scanner(System.in);
3. Use the methods next(), nextByte(), nextShort(),
nextInt(), nextLong(), nextFloat(), nextDouble(),
or nextBoolean() to obtain to a string, byte, short,
int, long, float, double, or boolean value. For
example,
System.out.print("Enter a double value:
");
Scanner scanner = new Scanner(System.in);
49. 49
TestScanner
TestScanner.java
import java.util.Scanner; // Scanner is in java.util
public class TestScanner {
public static void main(String args[]) {
// Create a Scanner
Scanner input = new Scanner(System.in);
// Prompt the user to enter an integer
System.out.print("Enter an integer: ");
int intValue = input.nextInt();
System.out.println("You entered the integer " + intValue);
// Prompt the user to enter a double value
System.out.print("Enter a double value: ");
double doubleValue = input.nextDouble();
System.out.println("You entered the double value " + doubleValue);
// Prompt the user to enter a string
System.out.print("Enter a string without space: ");
String string = input.next();
System.out.println("You entered the string " + string);
}
}
50. 50
Problem: Computing Loan Payments
This program lets the user enter the interest
rate, number of years, and loan amount and
computes monthly payment and total
payment.
12
)1(
11 ×
+
−
×
arsnumberOfYe
erestRatemonthlyInt
erestRatemonthlyIntloanAmount
51. 51
ComputeLoan.java
import java.util.Scanner;
public class ComputeLoan {
public static void main(String[] args) {
// Create a Scanner
Scanner input = new Scanner(System.in);
// Enter yearly interest rate
System.out.print("Enter yearly interest rate, for example 8.25: ");
double annualInterestRate = input.nextDouble();
// Obtain monthly interest rate
double monthlyInterestRate = annualInterestRate / 1200;
// Enter number of years
System.out.print( "Enter number of years as an integer, for example 5: ");
int numberOfYears = input.nextInt();
// Enter loan amount
System.out.print("Enter loan amount, for example 120000.95: ");
double loanAmount = input.nextDouble();
// Calculate payment
double monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / Math.pow(1 + monthlyInterestRate,
numberOfYears * 12));
double totalPayment = monthlyPayment * numberOfYears * 12;
// Format to keep two digits after the decimal point
monthlyPayment = (int)(monthlyPayment * 100) / 100.0;
totalPayment = (int)(totalPayment * 100) / 100.0;
// Display results System.out.println("The monthly payment is " + monthlyPayment);
System.out.println("The total payment is " + totalPayment);
}
}
52. 52
Problem: Monetary Units
This program lets the user enter the amount in
decimal representing dollars and cents and output
a report listing the monetary equivalent in single
dollars, quarters, dimes, nickels, and pennies.
Your program should report maximum number of
dollars, then the maximum number of quarters,
and so on, in this order.
53. 53
ComputeChange.java
import java.util.Scanner;
public class ComputeChange {
public static void main(String[] args) {
// Create a Scanner
Scanner input = new Scanner(System.in);
// Receive the amount
System.out.print( "Enter an amount in double, for example 11.56: ");
double amount = input.nextDouble();
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100; remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25; remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10; remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
// Display results
String output = "Your amount " + amount + " consists of n" + "t" + numberOfOneDollars + " dollarsn" + "t" +
numberOfQuarters + " quartersn" + "t" + numberOfDimes + " dimesn" + "t" + numberOfNickels + " nickelsn" + "t" +
numberOfPennies + " pennies"; System.out.println(output);
}
}
54. 54
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
1156remainingAmount
remainingAmount
initialized
Suppose amount is 11.56
55. 55
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
1156remainingAmount
Suppose amount is 11.56
11numberOfOneDollars
numberOfOneDollars
assigned
animation
56. 56
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
56remainingAmount
Suppose amount is 11.56
11numberOfOneDollars
remainingAmount
updated
animation
57. 57
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
56remainingAmount
Suppose amount is 11.56
11numberOfOneDollars
2numberOfOneQuarters
numberOfOneQuarters
assigned
animation
58. 58
Trace ComputeChange
int remainingAmount = (int)(amount * 100);
// Find the number of one dollars
int numberOfOneDollars = remainingAmount / 100;
remainingAmount = remainingAmount % 100;
// Find the number of quarters in the remaining amount
int numberOfQuarters = remainingAmount / 25;
remainingAmount = remainingAmount % 25;
// Find the number of dimes in the remaining amount
int numberOfDimes = remainingAmount / 10;
remainingAmount = remainingAmount % 10;
// Find the number of nickels in the remaining amount
int numberOfNickels = remainingAmount / 5;
remainingAmount = remainingAmount % 5;
// Find the number of pennies in the remaining amount
int numberOfPennies = remainingAmount;
6remainingAmount
Suppose amount is 11.56
11numberOfOneDollars
2numberOfQuarters
remainingAmount
updated
animation
59. 59
Problem: Displaying Current Time
Write a program that displays current time in GMT in the
format hour:minute:second such as 1:45:19.
The currentTimeMillis method in the System class
returns the current time in milliseconds since the
midnight, January 1, 1970 GMT. (1970 was the year
when the Unix operating system was formally
introduced.) You can use this method to obtain the
current time, and then compute the current second,
minute, and hour as follows.
Elapsed
time
Unix Epoch
01-01-1970
00:00:00 GMT
Current Time
Time
System.CurrentTimeMills()
60. 60
ShowCurrentTime.java
public class ShowCurrentTime {
public static void main(String[] args) {
// Obtain the total milliseconds since the midnight, Jan 1, 1970
long totalMilliseconds = System.currentTimeMillis();
// Obtain the total seconds since the midnight, Jan 1, 1970
long totalSeconds = totalMilliseconds / 1000;
// Compute the current second in the minute in the hour
int currentSecond = (int)(totalSeconds % 60);
// Obtain the total minutes
long totalMinutes = totalSeconds / 60;
// Compute the current minute in the hour
int currentMinute = (int)(totalMinutes % 60);
// Obtain the total hours
long totalHours = totalMinutes / 60;
// Compute the current hour
int currentHour = (int)(totalHours % 24);
// Display results
System.out.println("Current time is " + currentHour + ":" + currentMinute + ":" +
currentSecond + " GMT");
}
}
61. 61
Two Ways to Invoke the Method
There are several ways to use the showInputDialog method. For the
time being, you only need to know two ways to invoke it.
One is to use a statement as shown in the example:
import javax.swing.JOptionPane; //need to import the method
//the import goes before public class.
String string = JOptionPane.showInputDialog(null, x,
y, JOptionPane.QUESTION_MESSAGE);
where x is a string for the prompting message, and y is a string for
the title of the input dialog box.
The other is to use a statement like this:
JOptionPane.showInputDialog(x);
where x is a string for the prompting message.
62. 62
Getting Input from Input Dialog Boxes
String input = JOptionPane.showInputDialog(
"Enter an input");
64. 64
Converting Strings to Integers
The input returned from the input dialog box is a string. If you
enter a numeric value such as 123, it returns “123”. To obtain the
input as a number, you have to convert a string into a number.
To convert a string into an int value, you can use the static
parseInt method in the Integer class as follows:
String intString = JOptionPane.showInputDialog(null, “Enter
an integer”, “Integer Example”,
JOptionPane.QUESTION_MESSAGE);
int intValue = Integer.parseInt(intString);
where intString is a numeric string such as “123”.
65. 65
Converting Strings to Doubles
To convert a string into a double value, you can use the
static parseDouble method in the Double class as
follows:
String doubleString =
JOptionPane.showInputDialog(null, “Enter a double
value”, “Double Example”,
JOptionPane.QUESTION_MESSAGE);
double doubleValue =Double.parseDouble(doubleString);
where doubleString is a numeric string such as “123.45”.
66. 66
Dialog Box Input Conversion
Input from JOptionPane.showInputDialog is
a String type
Need to convert the input into type required
byte byteValue = Byte.parseByte(intString);
int intValue = Integer.parseInt(intString);
long longValue = Long.parserLong(intString);
float floatValue = Float.parseFloat(intString);
double doubleValue
=Double.parseDouble(doubleString);
Since the input value is a String, don’t need to
convert the input into a String type
67. 67
Problem: Computing Loan Payments Using Input Dialogs
ComputeLoanUsingInputDialogComputeLoanUsingInputDialog RunRun
Same as the preceding program for computing
loan payments, except that the input is entered
from the input dialogs and the output is displayed
in an output dialog.
12
)1(
11 ×
+
−
×
arsnumberOfYe
erestRatemonthlyInt
erestRatemonthlyIntloanAmount
68. 68
ComputeLoanUsingInputDialog
import javax.swing.JOptionPane;
public class ComputeLoanUsingInputDialog {
public static void main(String[] args) {
// Enter yearly interest rate
String annualInterestRateString = JOptionPane.showInputDialog( "Enter yearly interest rate, for example 8.25:");
// Convert string to double
double annualInterestRate = Double.parseDouble(annualInterestRateString);
// Obtain monthly interest rate
double monthlyInterestRate = annualInterestRate / 1200;
// Enter number of years
String numberOfYearsString = JOptionPane.showInputDialog( "Enter number of years as an integer, nfor example
5:");
// Convert string to int
int numberOfYears = Integer.parseInt(numberOfYearsString);
// Enter loan amount
String loanString = JOptionPane.showInputDialog( "Enter loan amount, for example 120000.95:");
// Convert string to double
double loanAmount = Double.parseDouble(loanString);
// Calculate payment
double monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / Math.pow(1 + monthlyInterestRate,
numberOfYears * 12));
double totalPayment = monthlyPayment * numberOfYears * 12;
// Format to keep two digits after the decimal point
monthlyPayment = (int)(monthlyPayment * 100) / 100.0;
totalPayment = (int)(totalPayment * 100) / 100.0;
// Display results
String output = "The monthly payment is " + monthlyPayment + "nThe total payment is " + totalPayment;
JOptionPane.showMessageDialog(null, output);
}
}
70. 70
Appropriate Comments
Include a summary at the beginning of the program to
explain what the program does, its key features, its
supporting data structures, and any unique techniques it
uses.
Include your name, due date, date submitted, program
name and a brief description at the beginning of the
program.
/****************************************
*
* Student Name:
* Date Due:
* Date Submitted:
* Program Name:
* Program Description:
*
****************************************/
71. 71
Naming Conventions
Choose meaningful and descriptive names.
Variables and method names:
Use lowercase. If the name consists of
several words, concatenate all in one, use
lowercase for the first word, and capitalize the
first letter of each subsequent word in the
name. For example, the variables radius and
area, and the method computeArea.
72. 72
Naming Conventions, cont.
Class names:
Capitalize the first letter of each word in
the name. For example, the class name
ComputeArea.
Constants:
Capitalize all letters in constants, and use
underscores to connect words. For
example, the constant PI and
MAX_VALUE
73. 73
Proper Indentation and Spacing
Indentation
Follow Eclipse indention.
Spacing
Use blank line to separate segments of the
code.
74. 74
Block Styles
Use end-of-line style for braces.
public class Test
{
public static void main(String[] args)
{
System.out.println("Block Styles");
}
}
public class Test {
public static void main(String[] args) {
System.out.println("Block Styles");
}
}
End-of-line
style
Next-line
style
75. 75
Programming Errors
Syntax Errors
Detected by the compiler
Runtime Errors
Causes the program to abort
Logic Errors
Produces incorrect result
76. 76
Syntax Errors
public class ShowSyntaxErrors {
public static void main(String[] args) {
i = 30;
System.out.println(i + 4);
}
}
Did not declare variable type for i
77. 77
Runtime Errors
public class ShowRuntimeErrors {
public static void main(String[] args) {
int i = 1 / 0;
}
}
Cannot divide by 0
78. 78
Logic Errors
public class ShowLogicErrors {
// Determine if a number is between 1 and 100 inclusively
public static void main(String[] args) {
// Prompt the user to enter a number
String input = JOptionPane.showInputDialog(null,
"Please enter an integer:",
"ShowLogicErrors", JOptionPane.QUESTION_MESSAGE);
int number = Integer.parseInt(input);
// Display the result
System.out.println("The number is between 1 and 100, " +
"inclusively? " + ((1 < number) && (number < 100)));
System.exit(0);
}
}
Does not print correct results for number2
79. 79
Debugging
Logic errors are called bugs. The process of finding and
correcting errors is called debugging. A common approach
to debugging is to use a combination of methods to narrow
down to the part of the program where the bug is located.
You can hand-trace the program (i.e., catch errors by
reading the program), or you can insert print statements in
order to show the values of the variables or the execution
flow of the program. This approach might work for a short,
simple program. But for a large, complex program, the
most effective approach for debugging is to use a debugger
utility.
80. 80
Debugger
Debugger is a program that facilitates debugging.
You can use a debugger to
Execute a single statement at a time.
Trace into or stepping over a method.
Set breakpoints.
Display variables.
Display call stack.
Modify variables.