In Java 8, the java.util.function has numerous built-in interfaces. Other packages in the Java library (notably java.util.stream package) make use of the interfaces defined in this package. Java 8 developers should be familiar with using key interfaces provided in this package. This presentation provides an overview of four key functional interfaces (Consumer, Supplier, Function, and Predicate) provided in this package.
In Java 8, the java.util.function has numerous built-in interfaces. Other packages in the Java library (notably java.util.stream package) make use of the interfaces defined in this package. Java 8 developers should be familiar with using key interfaces provided in this package. This presentation provides an overview of four key functional interfaces (Consumer, Supplier, Function, and Predicate) provided in this package.
Slides for a lightning talk on Java 8 lambda expressions I gave at the Near Infinity (www.nearinfinity.com) 2013 spring conference.
The associated sample code is on GitHub at https://github.com/sleberknight/java8-lambda-samples
Learn about how to define and invoke methods in Java, how to use parameters and return results. Watch the video lesson here:
https://softuni.org/code-lessons/java-foundations-certification-methods
In this core java training session, you will learn Collections - Maps. Topics covered in this session are:
• Collections – Maps
• Map Interface
• Map methods
• Mapuse
• Hashmap
• Treemap
• Utilities
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
In this chapter we will get more familiar with what methods are and why we need to use them. The reader will be shown how to declare methods, what parameters are and what a method’s signature is, how to call a method, how to pass arguments of methods and how methods return values. At the end of this chapter we will know how to create our own method and how to use (invoke) it whenever necessary. Eventually, we will suggest some good practices in working with methods. The content of this chapter accompanied by detailed examples and exercises that will help the reader practice the learned material.
Slides for a lightning talk on Java 8 lambda expressions I gave at the Near Infinity (www.nearinfinity.com) 2013 spring conference.
The associated sample code is on GitHub at https://github.com/sleberknight/java8-lambda-samples
Learn about how to define and invoke methods in Java, how to use parameters and return results. Watch the video lesson here:
https://softuni.org/code-lessons/java-foundations-certification-methods
In this core java training session, you will learn Collections - Maps. Topics covered in this session are:
• Collections – Maps
• Map Interface
• Map methods
• Mapuse
• Hashmap
• Treemap
• Utilities
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
In this chapter we will get more familiar with what methods are and why we need to use them. The reader will be shown how to declare methods, what parameters are and what a method’s signature is, how to call a method, how to pass arguments of methods and how methods return values. At the end of this chapter we will know how to create our own method and how to use (invoke) it whenever necessary. Eventually, we will suggest some good practices in working with methods. The content of this chapter accompanied by detailed examples and exercises that will help the reader practice the learned material.
In this lesson you will learn how to use basic syntax, conditions, if-else statements and loops (for-loop, while-loop and do-while-loop) in Java and how to use the debugger.
Watch the video lesson and access the hands-on exercises here: https://softuni.org/code-lessons/java-foundations-certification-basic-syntax-conditions-and-loops
OXUS 20 is pleased to offer PART I of Java Programming Questions and Answers with details explanation to support the educational needs and hoping these series help and benefit Computer Science student, IT professionals and those who eager to learn programming and in particular Java Programming...
you will learn how to create your own methods with or without return values, invoke a method with or without parameters, and apply method abstraction in the program design.
Q3 GIVEN THE TREND EQUATION NO OF STUDENTS-3000+200 YEAR BASE: 2003-0
1.INTERPRET EQUATION RESULTS 2.FORECAST FOR 2020 3.WHEN WILL THE NO OF
STUDENTS REACH 6000
Solution
x no of years from 2003 y no of students y = 3000+200x 1) The regression
equation has a positive slope of 200 y intercept is 3000 i.e. no of students in the year 2000
Thus for every year 200 students increase 2) For 2020, x = 17, y = 3000+200(17) = 6400
3) When y =6000, 6000 = 3000+200x or x = 15 Hence in year 2018 students reach 6000
B Regression C D. All the above.
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.
Characteristics of Java and basic programming constructs like Data types, Variables, Operators, Control Statements, Arrays are discussed with relevant examples
17. Java data structures trees representation and traversalIntro C# Book
In this chapter we will discuss tree data structures, like trees and graphs. The abilities of these data structures are really important for the modern programming. Each of this data structures is used for building a model of real life problems, which are efficiently solved using this model.
In this chapter we will discuss one recommended practice for efficiently solving computer programming problems and make a demonstration with appropriate examples. We will discuss the basic engineering principles of problem solving, why we should follow them when solving computer programming problems (the same principles can also be applied to find the solutions of many mathematical and scientific problems as well) and we will make an example of their use. We will describe the steps, in which we should go in order to solve some sample problems and show the mistakes that can occur when we do not follow these same steps. We will pay attention to some important steps from the methodology of problem solving, that we usually skip, e.g. the testing. We hope to be able to prove you, with proper examples, that the solving of computer programming problems has a "recipe" and it is very useful.
In this chapter we review the basic rules and recommendations for writing quality program code. We pay attention to naming the identifiers in the program (variables, methods, parameters, classes, etc.), formatting and code organization rules, good practices for composing methods, and principles for writing quality documentation.
Here we are going to learn why is a good practice to use interfaces and how they are different from abstraction classes. Further more we are going to see how which one of them to use.
19. Java data structures algorithms and complexityIntro C# Book
In this chapter we will compare the data structures we have learned so far by the performance (execution speed) of the basic operations (addition, search, deletion, etc.). We will give specific tips in what situations what data structures to use.
In this chapter we will understand how to define custom classes and their elements. We will learn to declare fields, constructors and properties for the classes. We will revise what a method is and we will broaden our knowledge about access modifiers and methods.
In this chapter we will explore strings. We are going to explain how they are implemented in Java and in what way we can process text content. Additionally, we will go through different methods for manipulating a text: we will learn how to compare strings, how to search for substrings, how to extract substrings upon previously settled parameters and last but not least how to split a string by separator chars. We will demonstrate how to correctly build strings with the StringBuilder class. We will provide a short but very useful information for the most commonly used regular expressions.
In this chapter we will discuss exceptions in the object-oriented programming and in Java in particular. We will learn how to handle exceptions using the try-catch construct, how to pass them to the calling methods and how to throw standard or our own exceptions using the throw construct.
Here we are going to take a look how to use for loop, foreach loop and while loop. Also we are going to learn how to use and invoke methods and how to define classes in Java programming language.
03 and 04 .Operators, Expressions, working with the console and conditional s...Intro C# Book
In this chapter we will get acquainted with the operators in Java and the actions they can perform on the different data types. We will explain the priorities of the operators and we will analyze the different types of operators, according to the count of the arguments they can take and the actions they can perform. In the second part we will examine the conversion of data types.
01. Introduction to programming with javaIntro C# Book
In this chapter we will take a look at the basic programming terminology and we will write our first Java program. We will familiarize ourselves with programming – what it means and its connection to computers and programming languages.
In this chapter we will discuss one recommended practice for efficiently solving computer programming problems and make a demonstration with appropriate examples. We will discuss the basic engineering principles of problem solving, why we should follow them when solving computer programming problems (the same principles can also be applied to find the solutions of many mathematical and scientific problems as well) and we will make an example of their use. We will describe the steps, in which we should go in order to solve some sample problems and show the mistakes that can occur when we do not follow these same steps. We will pay attention to some important steps from the methodology of problem solving, that we usually skip, e.g. the testing. We hope to be able to prove you, with proper examples, that the solving of computer programming problems has a "recipe" and it is very useful
Chapter 22. Lambda Expressions and LINQIntro C# Book
In this chapter we will become acquainted with some of the advanced capabilities of the C# language. To be more specific, we will pay attention on how to make queries to collections, using lambda expressions and LINQ, and how to add functionality to already created classes, using extension methods. We will get to know the anonymous types, describe their usage briefly and discuss lambda expressions and show in practice how most of the built-in lambda functions work. Afterwards, we will pay more attention to the LINQ syntax – we will learn what it is, how it works and what queries we can build with it. In the end, we will get to know the meaning of the keywords in LINQ, and demonstrate their capabilities with lots of examples.
This 7-second Brain Wave Ritual Attracts Money To You.!nirahealhty
Discover the power of a simple 7-second brain wave ritual that can attract wealth and abundance into your life. By tapping into specific brain frequencies, this technique helps you manifest financial success effortlessly. Ready to transform your financial future? Try this powerful ritual and start attracting money today!
# Internet Security: Safeguarding Your Digital World
In the contemporary digital age, the internet is a cornerstone of our daily lives. It connects us to vast amounts of information, provides platforms for communication, enables commerce, and offers endless entertainment. However, with these conveniences come significant security challenges. Internet security is essential to protect our digital identities, sensitive data, and overall online experience. This comprehensive guide explores the multifaceted world of internet security, providing insights into its importance, common threats, and effective strategies to safeguard your digital world.
## Understanding Internet Security
Internet security encompasses the measures and protocols used to protect information, devices, and networks from unauthorized access, attacks, and damage. It involves a wide range of practices designed to safeguard data confidentiality, integrity, and availability. Effective internet security is crucial for individuals, businesses, and governments alike, as cyber threats continue to evolve in complexity and scale.
### Key Components of Internet Security
1. **Confidentiality**: Ensuring that information is accessible only to those authorized to access it.
2. **Integrity**: Protecting information from being altered or tampered with by unauthorized parties.
3. **Availability**: Ensuring that authorized users have reliable access to information and resources when needed.
## Common Internet Security Threats
Cyber threats are numerous and constantly evolving. Understanding these threats is the first step in protecting against them. Some of the most common internet security threats include:
### Malware
Malware, or malicious software, is designed to harm, exploit, or otherwise compromise a device, network, or service. Common types of malware include:
- **Viruses**: Programs that attach themselves to legitimate software and replicate, spreading to other programs and files.
- **Worms**: Standalone malware that replicates itself to spread to other computers.
- **Trojan Horses**: Malicious software disguised as legitimate software.
- **Ransomware**: Malware that encrypts a user's files and demands a ransom for the decryption key.
- **Spyware**: Software that secretly monitors and collects user information.
### Phishing
Phishing is a social engineering attack that aims to steal sensitive information such as usernames, passwords, and credit card details. Attackers often masquerade as trusted entities in email or other communication channels, tricking victims into providing their information.
### Man-in-the-Middle (MitM) Attacks
MitM attacks occur when an attacker intercepts and potentially alters communication between two parties without their knowledge. This can lead to the unauthorized acquisition of sensitive information.
### Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) Attacks
Multi-cluster Kubernetes Networking- Patterns, Projects and GuidelinesSanjeev Rampal
Talk presented at Kubernetes Community Day, New York, May 2024.
Technical summary of Multi-Cluster Kubernetes Networking architectures with focus on 4 key topics.
1) Key patterns for Multi-cluster architectures
2) Architectural comparison of several OSS/ CNCF projects to address these patterns
3) Evolution trends for the APIs of these projects
4) Some design recommendations & guidelines for adopting/ deploying these solutions.
APNIC Foundation, presented by Ellisha Heppner at the PNG DNS Forum 2024APNIC
Ellisha Heppner, Grant Management Lead, presented an update on APNIC Foundation to the PNG DNS Forum held from 6 to 10 May, 2024 in Port Moresby, Papua New Guinea.
1.Wireless Communication System_Wireless communication is a broad term that i...JeyaPerumal1
Wireless communication involves the transmission of information over a distance without the help of wires, cables or any other forms of electrical conductors.
Wireless communication is a broad term that incorporates all procedures and forms of connecting and communicating between two or more devices using a wireless signal through wireless communication technologies and devices.
Features of Wireless Communication
The evolution of wireless technology has brought many advancements with its effective features.
The transmitted distance can be anywhere between a few meters (for example, a television's remote control) and thousands of kilometers (for example, radio communication).
Wireless communication can be used for cellular telephony, wireless access to the internet, wireless home networking, and so on.
Bridging the Digital Gap Brad Spiegel Macon, GA Initiative.pptxBrad Spiegel Macon GA
Brad Spiegel Macon GA’s journey exemplifies the profound impact that one individual can have on their community. Through his unwavering dedication to digital inclusion, he’s not only bridging the gap in Macon but also setting an example for others to follow.
1. Defining and Using Methods, Overloads
Methods
Software University
http://softuni.bg
SoftUni Team
Technical Trainers
2. Table of Contents
1. What Is a Method?
2. Naming and Best Practices
3. Declaring and Invoking Methods
Void and Return Type Methods
4. Methods with Parameters
5. Value vs. Reference Types
6. Overloading Methods
7. Program Execution Flow 2
5. Simple Methods
Named block of code, that can be invoked later
Sample method definition:
Invoking (calling) the
method several times:
5
public static void printHello () {
System.out.println("Hello!");
}
Method named
printHello
printHello();
printHello();
Method body
always
surrounded
by { }
6. More manageable programming
Splits large problems into small pieces
Better organization of the program
Improves code readability
Improves code understandability
Avoiding repeating code
Improves code maintainability
Code reusability
Using existing methods several times
Why Use Methods?
6
7. Executes the code between the brackets
Does not return result
Void Type Method
7
public static void printHello() {
System.out.println("Hello");
}
public static void main(String[] args) {
System.out.println("Hello");
}
main() is
also a
method
Prints
"Hello" on
the console
9. Methods naming guidelines
Use meaningful method names
Method names should answer the question:
What does this method do?
If you cannot find a good name for a method, think
about whether it has a clear intent
Naming Methods
9
findStudent, loadReport, sine
Method1, DoSomething, HandleStuff, SampleMethod
10. Naming Method Parameters
Method parameters names
Preferred form: [Noun] or [Adjective] + [Noun]
Should be in camelCase
Should be meaningful
Unit of measure should be obvious
10
firstName, report, speedKmH,
usersList, fontSizeInPixels, font
p, p1, p2, populate, LastName, last_name, convertImage
11. Each method should perform a single, well-defined task
A Method's name should describe that task in a clear and
non-ambiguous way
Avoid methods longer than one screen
Split them to several shorter methods
Methods – Best Practices
11
private static void printReceipt() {
printHeader();
printBody();
printFooter();
}
Self documenting
and easy to test
12. Make sure to use correct indentation
Leave a blank line between methods, after loops and after
if statements
Always use curly brackets for loops and if statements bodies
Avoid long lines and complex expressions
Code Structure and Code Formatting
12
static void main(args) {
// some code…
// some more code…
}
static void main(args)
{
// some code…
// some more code…
}
14. Methods are declared inside a class
main() is also a method
Variables inside a method are local
public static void printText(String text) {
System.out.println(text);
}
Declaring Methods
14
Method NameType Parameters
Method
Body
15. Methods are first declared, then invoked (many times)
Methods can be invoked (called) by their name + ():
Invoking a Method
15
public static void printHeader() {
System.out.println("----------");
}
public static void main(String[] args) {
printHeader();
}
Method
Declaration
Method
Invocation
16. A method can be invoked from:
The main method – main()
Invoking a Method (2)
public static void main(String[] args) {
printHeader();
}
public static void printHeader() {
printHeaderTop();
printHeaderBottom();
}
static void crash() {
crash();
}
Some other method Its own body – recursion
18. Method parameters can be of any data type
Call the method with certain values (arguments)
Method Parameters
18
public static void main(String[] args) {
printNumbers(5, 10);
}
static void printNumbers(int start, int end) {
for (int i = start; i <= end; i++) {
System.out.printf("%d ", i);
}
}
Passing arguments
at invocation
Multiple parameters
separated by comma
19. You can pass zero or several parameters
You can pass parameters of different types
Each parameter has name and type
public static void printStudent(String name, int age, double grade) {
System.out.printf("Student: %s; Age: %d, Grade: %.2fn",
name, age, grade);
}
Method Parameters (2)
19
Parameter
type
Parameter
name
Multiple parameters
of different types
20. Create a method that prints the sign of an integer number n:
Problem: Sign of Integer Number
20
2 The number 2 is positive.
-5
The number 0 is zero.
Check your solution here: https://judge.softuni.bg/Contests/1260
0
The number -5 is negative.
21. Solution: Sign of Integer Number
21
public static void main(String[] args) {
printSign(Integer.parseInt(sc.nextLine()));
}
public static void printSign(int number) {
if (number > 0)
System.out.printf("The number %d is positive.", number);
else if (number < 0)
System.out.printf("The number %d is negative.", number);
else
System.out.printf("The number %d is zero.", number);
}
Check your solution here: https://judge.softuni.bg/Contests/1260
22. Write a method that receives a grade between 2.00 and 6.00
and prints the corresponding grade in words
2.00 - 2.99 - "Fail"
3.00 - 3.49 - "Poor"
3.50 - 4.49 - "Good"
4.50 - 5.49 - "Very good"
5.50 - 6.00 - "Excellent"
Problem Grades
22
3.33 Poor
4.50 Very good
2.99 Fail
Check your solution here: https://judge.softuni.bg/Contests/1260
23. public static void main(String[] args) {
printInWords(Double.parseDouble(sc.nextLine()));
}
public static void printInWords(double grade) {
String gradeInWords = "";
if (grade >= 2 && grade <= 2.99)
gradeInWords = "Fail";
//TODO: make the rest
System.out.println(gradeInWords);
}
Solution Grades
23
25. Create a method that prints a single line, consisting of numbers
from a given start to a given end:
Solution: Printing Triangle (1)
25
public static void printLine(int start, int end) {
for (int i = start; i <= end; i++) {
System.out.print(i + " ");
}
System.out.println();
}
Check your solution here: https://judge.softuni.bg/Contests/1260
26. Create a method that prints the first half (1..n) and then the
second half (n-1…1) of the triangle:
Solution: Printing Triangle (2)
26
public static void printTriangle(int n) {
for (int line = 1; line <= n; line++)
printLine(1, line);
for (int line = n - 1; line >= 1; line--)
printLine(1, line);
}
Method with
parameter n
Check your solution here: https://judge.softuni.bg/Contests/1260
Lines 1...n
Lines n-1…1
29. The Return Statement
The return keyword immediately stops
the method's execution
Returns the specified value
Void methods can be terminated by just using return
29
public static String readFullName(Scanner sc) {
String firstName = sc.nextLine();
String lastName = sc.nextLine();
return firstName + " " + lastName;
} Returns a String
30. Using the Return Values
Return value can be:
Assigned to a variable
Used in expression
Passed to another method
30
int max = getMax(5, 10);
double total = getPrice() * quantity * 1.20;
int age = Integer.parseInt(sc.nextLine());
31. Create a method which returns rectangle area
with given width and height
Problem: Calculate Rectangle Area
31Check your solution here: https://judge.softuni.bg/Contests/1260
3
4
12
5
10
50
6
8
48
7
8
56
32. Solution: Calculate Rectangle Area
32
public static double calcRectangleArea(double width,
double height) {
return width * height;
}
public static void main(String[] args) {
double width = Double.parseDouble(sc.nextLine());
double height = Double.parseDouble(sc.nextLine());
double area = calcRectangleArea(width, height);
System.out.printf("%.0f%n",area);
}
Check your solution here: https://judge.softuni.bg/Contests/1260
33. Write a method that receives a string and a repeat count n
The method should return a new string
Problem: Repeat String
33
abc
3
abcabcabc
String
2
StringString
Check your solution here: https://judge.softuni.bg/Contests/1260
34. public static void main(String[] args) {
String inputStr = sc.nextLine();
int count = Integer.parseInt(sc.nextLine());
System.out.println(repeatString(inputStr, count));
}
private static String repeatString(String str, int count) {
String result = "";
for (int i = 0; i < count; i++) result += str;
return result;
}
Solution: Repeat String
34
35. Create a method that calculates and returns the value of a
number raised to a given power
Problem: Math Power
35
public static double mathPower(double number, int power) {
double result = 1;
for (int i = 0; i < power; i++)
result *= number;
return result;
}
5.5325628
Check your solution here: https://judge.softuni.bg/Contests/1260
166.375
39. Value type variables hold directly their value
int, float, double,
boolean, char, …
Each variable has its
own copy of the value
Value Types
39
int i = 42;
char ch = 'A';
boolean result = true;
Stack
42
A
true
(4 bytes)
(2 bytes)
(1 byte)
result
ch
i
40. Reference type variables hold а reference
(pointer / memory address) of the value itself
String, int[], char[], String[]
Two reference type variables can reference the
same object
Operations on both variables access / modify
the same data
Reference Types
40
41. Value Types vs. Reference Types
41
int i = 42;
char ch = 'A';
boolean result = true;
Object obj = 42;
String str = "Hello";
byte[] bytes ={ 1, 2, 3 };
HEAPSTACK
true (1 byte)
result
A (2 bytes)
ch
42 (4 bytes)
i
int32@9ae764
obj
42 4 bytes
String@7cdaf2
str
Hello String
byte[]@190d11
bytes
1 2 3 byte []
42. Example: Value Types
42
public static void main(String[] args) {
int num = 5;
increment(num, 15);
System.out.println(num);
}
public static void increment(int num, int value) {
num += value;
}
num == 5
num == 20
46. The combination of method's name and parameters
is called signature
Signature differentiates between methods with same names
When methods with the same name have different signature,
this is called method "overloading"
public static void print(String text) {
System.out.println(text);
}
Method Signature
46
Method's
signature
47. Using the same name for multiple methods with different
signatures (method name and parameters)
Overloading Methods
47
Different
method
signatures
static void print(int number) {
System.out.println(number);
}
static void print(String text) {
System.out.println(text);
}
static void print(String text, int number) {
System.out.println(text + ' ' + number);
}
48. Method's return type is not part of its signature
How would the compiler know which method to call?
Signature and Return Type
48
public static void print(String text) {
System.out.println(text);
}
public static String print(String text) {
return text;
}
Compile-time
error!
49. Create a method getMax() that returns the greater of two
values (the values can be of type int, char or String)
Problem: Greater of Two Values
49
z
char
a
z
16
int
2
16
bbb
String
aaa
bbb
Check your solution here: https://judge.softuni.bg/Contests/1260
52. public static void printLogo() {
System.out.println("Company Logo");
System.out.println("http://www.companywebsite.com");
}
public static void main(String[] args) {
System.out.println("before method executes");
printLogo();
System.out.println("after method executes");
}
The program continues, after a method execution completes:
Program Execution
53. Main
"The stack" stores information about the active subroutines
(methods) of a computer program
Keeps track of the point to which each active subroutine should
return control when it finishes executing
Program Execution – Call Stack
Method BMethod AMain
Call Stack
call
START Method A Method B
call
returnreturn
54. Create a program that multiplies the sum of all even digits of a
number by the sum of all odd digits of the same number:
Create a method called getMultipleOfEvensAndOdds()
Create a method getSumOfEvenDigits()
Create getSumOfOddDigits()
You may need to use Math.abs() for negative numbers
Problem: Multiply Evens by Odds
Evens: 2 4
Odds: 1 3 5
-12345
Even sum: 6
Odd sum: 9
54
Check your solution here: https://judge.softuni.bg/Contests/1260
56. …
…
…
Summary
56
Break large programs into simple
methods that solve small sub-problems
Methods consist of declaration and body
Methods are invoked by their name + ()
Methods can accept parameters
Methods can return a value
or nothing (void)
60. Software University – High-Quality Education and
Employment Opportunities
softuni.bg
Software University Foundation
http://softuni.foundation/
Software University @ Facebook
facebook.com/SoftwareUniversity
Software University Forums
forum.softuni.bg
Trainings @ Software University (SoftUni)
61. This course (slides, examples, demos, videos, homework, etc.)
is licensed under the "Creative Commons Attribution-NonCom
mercial-ShareAlike 4.0 International" license
License
61
Editor's Notes
(c) 2007 National Academy for Software Development - http://academy.devbg.org. All rights reserved. Unauthorized copying or re-distribution is strictly prohibited.*
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(c) 2007 National Academy for Software Development - http://academy.devbg.org. All rights reserved. Unauthorized copying or re-distribution is strictly prohibited.*