π Roadmap to Become a Java Developer π°
π Programming Basics
ββπ Master Java Syntax, Variables & Data Types
βββπ Learn Control Flow, Loops & Exception Handling
ββββπ Practice with Basic Programs
π Object-Oriented Programming (OOP)
ββπ Understand Classes, Objects & Inheritance
βββπ Dive into Encapsulation, Polymorphism & Abstraction
ββββπ Explore Design Patterns in Java
π Tools & Build Systems
ββπ Get Comfortable with IDEs (e.g., IntelliJ, Eclipse)
βββπ Master Maven & Gradle for Dependency Management
ββββπ Learn Git & Version Control Systems
π Data Structures & Algorithms
ββπ Learn Java Collections (Lists, Sets, Maps, etc.)
βββπ Understand Algorithms & Problem Solving
ββββπ Tackle Coding Challenges
π Web Development & APIs
ββπ Learn Servlets & JSP Basics
βββπ Dive into Spring Boot & RESTful Services
ββββπ Understand Microservices Architecture
π Database & Persistence
ββπ Master JDBC & SQL Fundamentals
βββπ Explore ORM Tools like Hibernate & JPA
ββββπ Practice with Real-World Data
π Testing & Debugging
ββπ Get Started with JUnit & Test-Driven Development
βββπ Learn Debugging Techniques & Best Practices
ββββπ Automate Testing with Tools
π Advanced Topics
ββπ Learn Multithreading & Concurrency
βββπ Understand JVM Internals & Garbage Collection
ββββπ Explore Performance Optimization
π Projects & Real-World Applications
ββπ Build End-to-End Java Applications
βββπ Contribute to Open-Source Projects
ββββπ Showcase on GitHub & Portfolio
π Interview Preparation & Job Hunting
ββπ Solve Java Coding Challenges
βββπ Master System Design & Architecture Concepts
ββββπ Network & Apply for Java Roles
β οΈ Get Hired
React "β€οΈ" for More π¨βπ»
π Programming Basics
ββπ Master Java Syntax, Variables & Data Types
βββπ Learn Control Flow, Loops & Exception Handling
ββββπ Practice with Basic Programs
π Object-Oriented Programming (OOP)
ββπ Understand Classes, Objects & Inheritance
βββπ Dive into Encapsulation, Polymorphism & Abstraction
ββββπ Explore Design Patterns in Java
π Tools & Build Systems
ββπ Get Comfortable with IDEs (e.g., IntelliJ, Eclipse)
βββπ Master Maven & Gradle for Dependency Management
ββββπ Learn Git & Version Control Systems
π Data Structures & Algorithms
ββπ Learn Java Collections (Lists, Sets, Maps, etc.)
βββπ Understand Algorithms & Problem Solving
ββββπ Tackle Coding Challenges
π Web Development & APIs
ββπ Learn Servlets & JSP Basics
βββπ Dive into Spring Boot & RESTful Services
ββββπ Understand Microservices Architecture
π Database & Persistence
ββπ Master JDBC & SQL Fundamentals
βββπ Explore ORM Tools like Hibernate & JPA
ββββπ Practice with Real-World Data
π Testing & Debugging
ββπ Get Started with JUnit & Test-Driven Development
βββπ Learn Debugging Techniques & Best Practices
ββββπ Automate Testing with Tools
π Advanced Topics
ββπ Learn Multithreading & Concurrency
βββπ Understand JVM Internals & Garbage Collection
ββββπ Explore Performance Optimization
π Projects & Real-World Applications
ββπ Build End-to-End Java Applications
βββπ Contribute to Open-Source Projects
ββββπ Showcase on GitHub & Portfolio
π Interview Preparation & Job Hunting
ββπ Solve Java Coding Challenges
βββπ Master System Design & Architecture Concepts
ββββπ Network & Apply for Java Roles
β οΈ Get Hired
React "β€οΈ" for More π¨βπ»
π2π₯1
Java project ideas to help you practice your skills
1. ToDo List Application: Create a command-line or GUI-based application that allows users to create, manage, and organize their tasks.
2. Calculator: Build a simple calculator application that can perform basic arithmetic operations like addition, subtraction, multiplication, and division.
3. Library Management System: Design a system for managing library resources, including books, patrons, and borrowing records.
4. Chat Application: Develop a chat application that enables users to communicate in real-time, either as a desktop app or through a web interface.
5. Weather App: Create an app that fetches weather data from an API and displays current weather conditions for a given location.
6. Student Gradebook: Build a program to store and calculate student grades. You can add features like grade averages and report generation.
7. Expense Tracker: Create an application for tracking expenses and generating reports, helping users manage their finances.
8. Simple Game (e.g., Tic-Tac-Toe): Implement a classic game like Tic-Tac-Toe to learn about game logic and user interaction.
9. Blog or Content Management System (CMS): Build a simple blog or CMS where users can create, edit, and publish articles.
10. E-commerce Shopping Cart: Create a basic online shopping cart system with product listings, a shopping cart, and checkout functionality.
11. File Manager: Develop a file manager application that allows users to organize and manage files and directories on their computer.
12. Inventory System: Design an inventory management system for tracking products, quantities, and orders for a small business.
13. Music Player: Create a basic music player with features like play, pause, skip, and a library of songs.
14. Password Manager: Build a secure application for storing and managing passwords and other sensitive information.
15. Chess or Sudoku Solver: Implement a chess game or a Sudoku puzzle solver to delve into complex algorithms and logic.
16. Note-taking App: Develop a note-taking application with features like creating, editing, and organizing notes.
17. Expense Sharing App: Build an app for groups to track shared expenses and split bills among friends or roommates.
18. Task Scheduler: Create a program that allows users to schedule and manage tasks, reminders, and appointments.
19. Mini Social Media Platform: Create a simplified social media platform with features like user profiles, posting, and commenting.
20. Quiz or Flashcard Application: Design an app for creating and taking quizzes or using flashcards to study various topics.
Choose a project that aligns with your interests and skill level. As you work on these projects, you'll gain valuable experience and improve your Java programming skills.
1. ToDo List Application: Create a command-line or GUI-based application that allows users to create, manage, and organize their tasks.
2. Calculator: Build a simple calculator application that can perform basic arithmetic operations like addition, subtraction, multiplication, and division.
3. Library Management System: Design a system for managing library resources, including books, patrons, and borrowing records.
4. Chat Application: Develop a chat application that enables users to communicate in real-time, either as a desktop app or through a web interface.
5. Weather App: Create an app that fetches weather data from an API and displays current weather conditions for a given location.
6. Student Gradebook: Build a program to store and calculate student grades. You can add features like grade averages and report generation.
7. Expense Tracker: Create an application for tracking expenses and generating reports, helping users manage their finances.
8. Simple Game (e.g., Tic-Tac-Toe): Implement a classic game like Tic-Tac-Toe to learn about game logic and user interaction.
9. Blog or Content Management System (CMS): Build a simple blog or CMS where users can create, edit, and publish articles.
10. E-commerce Shopping Cart: Create a basic online shopping cart system with product listings, a shopping cart, and checkout functionality.
11. File Manager: Develop a file manager application that allows users to organize and manage files and directories on their computer.
12. Inventory System: Design an inventory management system for tracking products, quantities, and orders for a small business.
13. Music Player: Create a basic music player with features like play, pause, skip, and a library of songs.
14. Password Manager: Build a secure application for storing and managing passwords and other sensitive information.
15. Chess or Sudoku Solver: Implement a chess game or a Sudoku puzzle solver to delve into complex algorithms and logic.
16. Note-taking App: Develop a note-taking application with features like creating, editing, and organizing notes.
17. Expense Sharing App: Build an app for groups to track shared expenses and split bills among friends or roommates.
18. Task Scheduler: Create a program that allows users to schedule and manage tasks, reminders, and appointments.
19. Mini Social Media Platform: Create a simplified social media platform with features like user profiles, posting, and commenting.
20. Quiz or Flashcard Application: Design an app for creating and taking quizzes or using flashcards to study various topics.
Choose a project that aligns with your interests and skill level. As you work on these projects, you'll gain valuable experience and improve your Java programming skills.
β€7π2
Java Handwritten Notes.pdf
303.8 MB
Since Java Is Top 1 Check this β¬οΈ
(Python and other materials will send them very soon too βΌοΈ)
THE BIGGEST Java Handwritten Notes File Ever πβοΈ
Topics Covered in this E-Book
Chapter - 1 : Introduction to Java
Chapter - 2 : Getting Started with Java
Chapter - 3 : Control Structures
Chapter - 4 : Functions and Methods
Chapter - 5 : Object-Oriented in Java
Chapter - 6 : Collections and Generics
Chapter - 7 : Multithreading and Concurrency
Chapter - 8 : File I/O and Data Persistence
Chapter - 9 : User Interfaces with JavaFX
Chapter - 10 : Advanced Topics
Support with a Heart "β€οΈ" For More
(Python and other materials will send them very soon too βΌοΈ)
THE BIGGEST Java Handwritten Notes File Ever πβοΈ
Topics Covered in this E-Book
Chapter - 1 : Introduction to Java
Chapter - 2 : Getting Started with Java
Chapter - 3 : Control Structures
Chapter - 4 : Functions and Methods
Chapter - 5 : Object-Oriented in Java
Chapter - 6 : Collections and Generics
Chapter - 7 : Multithreading and Concurrency
Chapter - 8 : File I/O and Data Persistence
Chapter - 9 : User Interfaces with JavaFX
Chapter - 10 : Advanced Topics
Support with a Heart "β€οΈ" For More
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Useful Telegram Channels for Free Learning ππ
Free Courses with Certificate
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Free Courses with Certificate
Web Development
Data Science & Machine Learning
Programming books
Python Free Courses
Data Analytics
Ethical Hacking & Cyber Security
English Speaking & Communication
Stock Marketing & Investment Banking
Excel
ChatGPT Hacks
SQL
Tableau & Power BI
Coding Projects
Data Science Projects
Jobs & Internship Opportunities
Coding Interviews
Udemy Free Courses with Certificate
Cryptocurrency & Bitcoin
Python Projects
Data Analyst Interview
Data Analyst Jobs
Python Interview
ChatGPT Hacks
ENJOY LEARNING ππ
π4β€1
List of Java Project Ideas π‘π¨π»βπ»β
Beginner Projects
πΉ Calculator
πΉ To-Do List App
πΉ Number Guessing Game
πΉ Password Generator
πΉ Flashcard Quizzer
πΉ Simple Chatbot
πΉ Weather App
πΉ Unit Converter
πΉ Rock-Paper-Scissors Game
Intermediate Projects
πΈ Personal Diary
πΈ Web Scraping Tool
πΈ Expense Tracker
πΈ Spring Boot Blog
πΈ Image Gallery
πΈ Chat Application
πΈ Pomodoro Timer
πΈ Basic Game with JavaFX
Advanced Projects
πΊ Social Media Dashboard
πΊ Machine Learning Model
πΊ Data Visualization Tool
πΊ Blockchain Simulation
πΊ Chatbot with NLP
πΊ File Organizer
Free Java Resources: https://t.me/Java_Programming_Notes
Beginner Projects
πΉ Calculator
πΉ To-Do List App
πΉ Number Guessing Game
πΉ Password Generator
πΉ Flashcard Quizzer
πΉ Simple Chatbot
πΉ Weather App
πΉ Unit Converter
πΉ Rock-Paper-Scissors Game
Intermediate Projects
πΈ Personal Diary
πΈ Web Scraping Tool
πΈ Expense Tracker
πΈ Spring Boot Blog
πΈ Image Gallery
πΈ Chat Application
πΈ Pomodoro Timer
πΈ Basic Game with JavaFX
Advanced Projects
πΊ Social Media Dashboard
πΊ Machine Learning Model
πΊ Data Visualization Tool
πΊ Blockchain Simulation
πΊ Chatbot with NLP
πΊ File Organizer
Free Java Resources: https://t.me/Java_Programming_Notes
π5β€3
β
List and Set in Java Collections Framework :
π LIST :
πΈ List in Java provides the facility to maintain the ordered collection.
πΉ It contains the index-based methods to insert, update, delete and search the elements.
πΈ It can have the duplicate elements also.
πΉ We can also store the null elements in the list.
π SET :
πΈ Set interface in Java is present in jave.util package.
πΉIt extends the Collection interface.
πΈ It represents the unordered set of elements which doesn't allow us to store the duplicate items.
πΉ We can store at most one null value in Set.
πΈ Set is implemented by HashSet, LinkedHashSet and TreeSet.
Like for more β€οΈ
π LIST :
πΈ List in Java provides the facility to maintain the ordered collection.
πΉ It contains the index-based methods to insert, update, delete and search the elements.
πΈ It can have the duplicate elements also.
πΉ We can also store the null elements in the list.
π SET :
πΈ Set interface in Java is present in jave.util package.
πΉIt extends the Collection interface.
πΈ It represents the unordered set of elements which doesn't allow us to store the duplicate items.
πΉ We can store at most one null value in Set.
πΈ Set is implemented by HashSet, LinkedHashSet and TreeSet.
Like for more β€οΈ
π2β€1
π PERFORMANCE TUNING: Boost Your System Like a Pro! β‘οΈ
Is your application slow? Facing database bottlenecks? Or maybe network issues? Performance tuning is the key! Hereβs a breakdown of essential optimization areas to supercharge your system:
πΉ Code Tuning π₯
Optimize your code by managing CPU, memory, and other resources efficiently. A few tweaks can make a BIG difference!
πΉ Infrastructure Tuning π
Benchmark, scale, and optimize storage to ensure your hardware and cloud infrastructure are performing at their best.
πΉ Architecture Tuning βοΈ
Implement caching, loose coupling, and asynchronous processing for a seamless and scalable system.
πΉ Configuration Tuning βοΈ
Fine-tune your app's settings for maximum efficiencyβmaster configuration tuning is crucial!
πΉ Network Tuning π
Reduce latency, optimize traffic flow, and secure your network with firewall & DNS adjustments.
πΉ Database Tuning π
Optimize queries, indexes, and partitions to speed up data retrieval and improve overall DB performance.
Is your application slow? Facing database bottlenecks? Or maybe network issues? Performance tuning is the key! Hereβs a breakdown of essential optimization areas to supercharge your system:
πΉ Code Tuning π₯
Optimize your code by managing CPU, memory, and other resources efficiently. A few tweaks can make a BIG difference!
πΉ Infrastructure Tuning π
Benchmark, scale, and optimize storage to ensure your hardware and cloud infrastructure are performing at their best.
πΉ Architecture Tuning βοΈ
Implement caching, loose coupling, and asynchronous processing for a seamless and scalable system.
πΉ Configuration Tuning βοΈ
Fine-tune your app's settings for maximum efficiencyβmaster configuration tuning is crucial!
πΉ Network Tuning π
Reduce latency, optimize traffic flow, and secure your network with firewall & DNS adjustments.
πΉ Database Tuning π
Optimize queries, indexes, and partitions to speed up data retrieval and improve overall DB performance.
β€1π1
2 Month Roadmap to learn Java and Spring from basics to advanced
Week 1-2: Core Java
- Basic Syntax: Data types, operators, loops (for, while, do-while)
- OOP Concepts: Classes, objects, inheritance, polymorphism, encapsulation, abstraction
- Collections Framework: List, Set, Map, Queue, Iterator, etc.
- Exception Handling: Try-catch, custom exceptions, multi-catch
- File I/O: Reading/writing files using java.io and java.nio
- Java 8+ Features: Lambdas, Streams, Optional, Functional Interfaces
- Multithreading: Threads, Runnable, ExecutorService, Future, and basic synchronization
Week 3-4: Advanced Java & JDBC
- JVM Internals: ClassLoader, JIT, memory management, garbage collection
- Generics: Usage and wildcards
- Design Patterns: Singleton, Factory, Strategy, Observer, Dependency Injection (Intro)
- JDBC: Connecting with databases (CRUD operations), PreparedStatement, Connection pooling
Week 5-6: Spring Framework (Basics)
- Spring Core
- Dependency Injection (DI) and Inversion of Control (IoC)
- Beans, Scopes, and Bean Life Cycle
- Autowiring and Spring Annotations
- Spring AOP: Aspect-Oriented Programming fundamentals
- Spring Data JPA: Basic CRUD operations with JPA
- Entities, Repositories, and Custom Queries
Week 7: Spring Boot (Basics)
- Spring Boot Fundamentals: Understanding the Spring Boot architecture
- REST API creation
- Spring Boot Annotations (@RestController, @RequestMapping, etc.)
- Running a Spring Boot application
- Spring Boot Auto Configuration: Application properties and profiles
- Spring Boot with Database: Integrate Spring Boot with MySQL using Spring Data JPA
Week 8: Spring Boot (Advanced)
- Security: Introduction to Spring Security (Basic Authentication)
- Advanced Spring Boot Features: Exception handling (@ControllerAdvice)
- Logging with Spring Boot
- Pagination and Sorting
- Testing: Write unit tests using JUnit and Mockito in Spring Boot
Like for more β€οΈ
Week 1-2: Core Java
- Basic Syntax: Data types, operators, loops (for, while, do-while)
- OOP Concepts: Classes, objects, inheritance, polymorphism, encapsulation, abstraction
- Collections Framework: List, Set, Map, Queue, Iterator, etc.
- Exception Handling: Try-catch, custom exceptions, multi-catch
- File I/O: Reading/writing files using java.io and java.nio
- Java 8+ Features: Lambdas, Streams, Optional, Functional Interfaces
- Multithreading: Threads, Runnable, ExecutorService, Future, and basic synchronization
Week 3-4: Advanced Java & JDBC
- JVM Internals: ClassLoader, JIT, memory management, garbage collection
- Generics: Usage and wildcards
- Design Patterns: Singleton, Factory, Strategy, Observer, Dependency Injection (Intro)
- JDBC: Connecting with databases (CRUD operations), PreparedStatement, Connection pooling
Week 5-6: Spring Framework (Basics)
- Spring Core
- Dependency Injection (DI) and Inversion of Control (IoC)
- Beans, Scopes, and Bean Life Cycle
- Autowiring and Spring Annotations
- Spring AOP: Aspect-Oriented Programming fundamentals
- Spring Data JPA: Basic CRUD operations with JPA
- Entities, Repositories, and Custom Queries
Week 7: Spring Boot (Basics)
- Spring Boot Fundamentals: Understanding the Spring Boot architecture
- REST API creation
- Spring Boot Annotations (@RestController, @RequestMapping, etc.)
- Running a Spring Boot application
- Spring Boot Auto Configuration: Application properties and profiles
- Spring Boot with Database: Integrate Spring Boot with MySQL using Spring Data JPA
Week 8: Spring Boot (Advanced)
- Security: Introduction to Spring Security (Basic Authentication)
- Advanced Spring Boot Features: Exception handling (@ControllerAdvice)
- Logging with Spring Boot
- Pagination and Sorting
- Testing: Write unit tests using JUnit and Mockito in Spring Boot
Like for more β€οΈ
π5
Java Basics every beginner should learn to build a strong foundation:
1. Hello World & Setup
Install JDK and an IDE (like IntelliJ or Eclipse)
Write your first program: public class HelloWorld
2. Data Types & Variables
Primitive types: int, double, char, boolean
Non-primitive types: String, Arrays, Objects
Type casting (implicit & explicit)
3. Operators
Arithmetic: + - * / %
Comparison: == != > < >= <=
Logical: && || !
4. Control Flow
If, else if, else
Switch-case
Loops: for, while, do-while
break and continue
5. Functions (Methods)
Syntax: public static returnType methodName(params)
Method overloading
Return types & parameter passing
6. Object-Oriented Programming (OOP)
Classes & Objects
this keyword
Constructors (default & parameterized)
7. OOP Concepts
Encapsulation (private variables + getters/setters)
Inheritance (extends keyword)
Polymorphism (method overriding)
Abstraction (abstract classes & interfaces)
8. Arrays & ArrayList
Declaring and iterating arrays
ArrayList methods: add, remove, get, size
Multidimensional arrays
9. Exception Handling
Try-catch-finally blocks
throw and throws
Custom exceptions
10. Basic Input/Output
Scanner class for user input
System.out.println() for output
Free Java Resources: https://whatsapp.com/channel/0029VamdH5mHAdNMHMSBwg1s
ENJOY LEARNING ππ
1. Hello World & Setup
Install JDK and an IDE (like IntelliJ or Eclipse)
Write your first program: public class HelloWorld
2. Data Types & Variables
Primitive types: int, double, char, boolean
Non-primitive types: String, Arrays, Objects
Type casting (implicit & explicit)
3. Operators
Arithmetic: + - * / %
Comparison: == != > < >= <=
Logical: && || !
4. Control Flow
If, else if, else
Switch-case
Loops: for, while, do-while
break and continue
5. Functions (Methods)
Syntax: public static returnType methodName(params)
Method overloading
Return types & parameter passing
6. Object-Oriented Programming (OOP)
Classes & Objects
this keyword
Constructors (default & parameterized)
7. OOP Concepts
Encapsulation (private variables + getters/setters)
Inheritance (extends keyword)
Polymorphism (method overriding)
Abstraction (abstract classes & interfaces)
8. Arrays & ArrayList
Declaring and iterating arrays
ArrayList methods: add, remove, get, size
Multidimensional arrays
9. Exception Handling
Try-catch-finally blocks
throw and throws
Custom exceptions
10. Basic Input/Output
Scanner class for user input
System.out.println() for output
Free Java Resources: https://whatsapp.com/channel/0029VamdH5mHAdNMHMSBwg1s
ENJOY LEARNING ππ
π1π1
Typical java interview questions sorted by experience
Junior
* Name some of the characteristics of OO programming languages
* What are the access modifiers you know? What does each one do?
* What is the difference between overriding and overloading a method in Java?
* Whatβs the difference between an Interface and an abstract class?
* Can an Interface extend another Interface?
* What does the static word mean in Java?
* Can a static method be overridden in Java?
* What is Polymorphism? What about Inheritance?
* Can a constructor be inherited?
* Do objects get passed by reference or value in Java? Elaborate on that.
* Whatβs the difference between using == and .equals on a string?
* What is the hashCode() and equals() used for?
* What does the interface Serializable do? What about Parcelable in Android?
* Why are Array and ArrayList different? When would you use each?
* Whatβs the difference between an Integer and int?
* What is a ThreadPool? Is it better than using several βsimpleβ threads?
* What the difference between local, instance and class variables?
Mid
* What is reflection?
* What is dependency injection? Can you name a few libraries? (Have you used any?)
* What are strong, soft and weak references in Java?
* What does the keyword synchronized mean?
* Can you have βmemory leaksβ on Java?
* Do you need to set references to null on Java/Android?
* What does it means to say that a String is immutable?
* What are transient and volatile modifiers?
* What is the finalize() method?
* How does the try{} finally{} works?
* What is the difference between instantiation and initialisation of an object?
* When is a static block run?
* Why are Generics are used in Java?
* Can you mention the design patterns you know? Which of those do you normally use?
* Can you mention some types of testing you know?
Senior
* How does Integer.parseInt() works?
* Do you know what is the βdouble check lockingβ problem?
* Do you know the difference between StringBuffer and StringBuilder?
* How is a StringBuilder implemented to avoid the immutable string allocation problem?
* What does Class.forName method do?
* What is Autoboxing and Unboxing?
* Whatβs the difference between an Enumeration and an Iterator?
* What is the difference between fail-fast and fail safe in Java?
* What is PermGen in Java?
* What is a Java priority queue?
* *s performance influenced by using the same number in different types: Int, Double and Float?
* What is the Java Heap?
* What is daemon thread?
* Can a dead thread be restarted?
Source: medium.
Junior
* Name some of the characteristics of OO programming languages
* What are the access modifiers you know? What does each one do?
* What is the difference between overriding and overloading a method in Java?
* Whatβs the difference between an Interface and an abstract class?
* Can an Interface extend another Interface?
* What does the static word mean in Java?
* Can a static method be overridden in Java?
* What is Polymorphism? What about Inheritance?
* Can a constructor be inherited?
* Do objects get passed by reference or value in Java? Elaborate on that.
* Whatβs the difference between using == and .equals on a string?
* What is the hashCode() and equals() used for?
* What does the interface Serializable do? What about Parcelable in Android?
* Why are Array and ArrayList different? When would you use each?
* Whatβs the difference between an Integer and int?
* What is a ThreadPool? Is it better than using several βsimpleβ threads?
* What the difference between local, instance and class variables?
Mid
* What is reflection?
* What is dependency injection? Can you name a few libraries? (Have you used any?)
* What are strong, soft and weak references in Java?
* What does the keyword synchronized mean?
* Can you have βmemory leaksβ on Java?
* Do you need to set references to null on Java/Android?
* What does it means to say that a String is immutable?
* What are transient and volatile modifiers?
* What is the finalize() method?
* How does the try{} finally{} works?
* What is the difference between instantiation and initialisation of an object?
* When is a static block run?
* Why are Generics are used in Java?
* Can you mention the design patterns you know? Which of those do you normally use?
* Can you mention some types of testing you know?
Senior
* How does Integer.parseInt() works?
* Do you know what is the βdouble check lockingβ problem?
* Do you know the difference between StringBuffer and StringBuilder?
* How is a StringBuilder implemented to avoid the immutable string allocation problem?
* What does Class.forName method do?
* What is Autoboxing and Unboxing?
* Whatβs the difference between an Enumeration and an Iterator?
* What is the difference between fail-fast and fail safe in Java?
* What is PermGen in Java?
* What is a Java priority queue?
* *s performance influenced by using the same number in different types: Int, Double and Float?
* What is the Java Heap?
* What is daemon thread?
* Can a dead thread be restarted?
Source: medium.
π6
18 Most common used Java List methods
1. add(E element) - Adds the specified element to the end of the list.
2. addAll(Collection<? extends E> c) - Adds all elements of the specified collection to the end of the list.
3. remove(Object o) - Removes the first occurrence of the specified element from the list.
4. remove(int index) - Removes the element at the specified position in the list.
5. get(int index) - Returns the element at the specified position in the list.
6. set(int index, E element) - Replaces the element at the specified position in the list with the specified element.
7. indexOf(Object o) - Returns the index of the first occurrence of the specified element in the list.
8. contains(Object o) - Returns true if the list contains the specified element.
9. size() - Returns the number of elements in the list.
10. isEmpty() - Returns true if the list contains no elements.
11. clear() - Removes all elements from the list.
12. toArray() - Returns an array containing all the elements in the list.
13. subList(int fromIndex, int toIndex) - Returns a view of the portion of the list between the specified fromIndex, inclusive, and toIndex, exclusive.
14. addAll(int index, Collection<? extends E> c) - Inserts all elements of the specified collection into the list, starting at the specified position.
15. iterator() - Returns an iterator over the elements in the list.
16. sort(Comparator<? super E> c) - Sorts the elements of the list according to the specified comparator.
17. replaceAll(UnaryOperator<E> operator) - Replaces each element of the list with the result of applying the given operator.
18. forEach(Consumer<? super E> action) - Performs the given action for each element of the list until all elements have been processed or the action throws an exception.
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1. add(E element) - Adds the specified element to the end of the list.
2. addAll(Collection<? extends E> c) - Adds all elements of the specified collection to the end of the list.
3. remove(Object o) - Removes the first occurrence of the specified element from the list.
4. remove(int index) - Removes the element at the specified position in the list.
5. get(int index) - Returns the element at the specified position in the list.
6. set(int index, E element) - Replaces the element at the specified position in the list with the specified element.
7. indexOf(Object o) - Returns the index of the first occurrence of the specified element in the list.
8. contains(Object o) - Returns true if the list contains the specified element.
9. size() - Returns the number of elements in the list.
10. isEmpty() - Returns true if the list contains no elements.
11. clear() - Removes all elements from the list.
12. toArray() - Returns an array containing all the elements in the list.
13. subList(int fromIndex, int toIndex) - Returns a view of the portion of the list between the specified fromIndex, inclusive, and toIndex, exclusive.
14. addAll(int index, Collection<? extends E> c) - Inserts all elements of the specified collection into the list, starting at the specified position.
15. iterator() - Returns an iterator over the elements in the list.
16. sort(Comparator<? super E> c) - Sorts the elements of the list according to the specified comparator.
17. replaceAll(UnaryOperator<E> operator) - Replaces each element of the list with the result of applying the given operator.
18. forEach(Consumer<? super E> action) - Performs the given action for each element of the list until all elements have been processed or the action throws an exception.
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