Java Static Keyword & Access Modifiers Explained

🚀 Day 4 of My Java Learning Journey Today I learned how a Java program works internally and covered some important core concepts. 📌 Topics I Covered: 🔹 How to run a Java program • Compile using javac • Run using java • JVM executes the program 🔹 Main Method in Java public static void main(String[] args) • public → JVM can access it from anywhere • static → No need to create object • void → Does not return any value • main → Entry point of program 🔹 System.out.println() • System → class from java.lang package • out → object of PrintStream • println() → method used to print output 🔹 Variables in Java • A variable is a container to store data in memory (RAM) • Syntax: datatype variable_name = value; Example: int age = 35; System.out.println("The age is: " + age); 📌 Rules of Variables • Cannot contain spaces • Cannot start with a digit • Can use _ and $ symbols Building strong fundamentals in Java step by step and staying consistent every day. You can check my code here 👇 🔗 https://lnkd.in/gDP4A9r6 If you are also learning Java, let’s connect and grow together 🤝 #Java #JavaDeveloper #CodingJourney #Programming #LearningInPublic #SoftwareDevelopment

Deep Dive into Core Java Concepts 🚀 Today, I explored some important Java concepts including toString(), static members, and method behavior in inheritance. 🔹 The toString() method (from Object class) is used to represent an object in a readable format. By default, it returns "ClassName@hashcode", but by overriding it, we can display meaningful information. 🔹 Understanding static in Java: ✔️ Static variables and methods are inherited ❌ Static methods cannot be overridden ✔️ Static methods can be hidden (method hiding) 🔹 What is Method Hiding? If a subclass defines a static method with the same name and parameters as the parent class, it is called method hiding, not overriding. 🔹 Key Difference: ➡️ Overriding → applies to instance methods (runtime polymorphism) ➡️ Method Hiding → applies to static methods (compile-time behavior) 🔹 Also revised execution flow: ➡️ Static blocks (Parent → Child) ➡️ Instance blocks (Parent → Child) ➡️ Constructors (Parent → Child) This learning helped me clearly understand how Java handles inheritance, memory, and method behavior internally. Continuing to strengthen my Core Java fundamentals 💻🔥 #Java #OOP #CoreJava #Programming #LearningJourney #Coding

🚀 Learning Update: Java Encapsulation, POJO Classes & Real-World Object Handling Today’s live session helped me understand how Encapsulation works practically in Java by building a complete program step-by-step. 🔹 Encapsulation in Java Encapsulation protects data by making variables private and providing controlled access through public methods like getters and setters. 🔹 Building a POJO Class We created an Employee class with: • Private variables (empId, empName, empSalary) • Zero-parameterized constructor • Parameterized constructor • Getter and Setter methods This type of class is called a POJO (Plain Old Java Object) and is widely used in real-world Java applications. 🔹 Understanding the this Keyword The this keyword refers to the currently executing object and helps resolve the shadowing problem when local variables and instance variables have the same name. 🔹 Handling Multiple Objects Efficiently Instead of repeatedly creating objects, we used: ✔ Loops to handle multiple inputs ✔ Arrays of objects to store multiple Employee objects ✔ Scanner input handling to read user input dynamically 🔹 Important Debugging Insight While working with Scanner, I learned about the input buffer problem when mixing nextInt() and nextLine() and how to fix it by flushing the buffer. 🔹 Working with CSV Input & Wrapper Classes We also handled input like: 1,Alex,50000 Using: • split() method to separate values • Integer.parseInt() to convert String to integer • Wrapper classes for type conversion 💡 Key Takeaway Writing programs step-by-step and understanding how objects, constructors, arrays, and input handling work together makes Java concepts much clearer. Excited to keep improving my Core Java and problem-solving skills through continuous practice. #Java #Encapsulation #OOP #POJO #Programming #SoftwareDevelopment #LearningJourney #JavaDeveloper TAP Academy

🚀 Mastering Core Java | Day 14 📘 Topic: Key Methods to Pause Java Thread Execution Today’s learning focused on important methods used in Java multithreading to control or pause thread execution. Understanding these methods helps manage thread coordination and improves application performance. 🔹 Thread.sleep(milliseconds) Pauses the current thread for a specified time Moves the thread to TIMED_WAITING state Does not release locks Requires handling InterruptedException 🧩 Used when we want a thread to pause temporarily. 🔹 Object.wait() Causes the current thread to wait until another thread notifies it Moves thread to WAITING or TIMED_WAITING state Releases the object’s monitor lock Must be used inside a synchronized block 🧩 Commonly used for thread communication. 🔹 Thread.join() Makes the current thread wait for another thread to finish execution Moves thread to WAITING state Useful when tasks depend on completion of another thread 🧩 Ensures sequential dependency between threads. 🔹 Thread.yield() Suggests the scheduler to pause the current thread and allow others to run Moves thread from RUNNING → RUNNABLE state Not guaranteed to pause execution 🧩 Helps give equal opportunity to threads of the same priority. 💡 Key Takeaway: These methods help control thread scheduling, coordination, and execution flow, which is essential for building efficient, responsive, and high‑performance Java applications. Vaibhav Barde sir Grateful for the continuous learning that strengthens my Core Java and multithreading fundamentals step by step. #CoreJava #Multithreading #JavaThreads #JavaDeveloper #ThreadManagement #LearningJourney #Day14 #SoftwareDevelopment 🚀

🚀 Day 16 | Core Java Learning Journey 📌 Topic: this, super & final Keyword (Java Keywords – Part 2) Today, I explored three very important Java keywords that control object behavior, inheritance, and immutability. 🔹 this Keyword in Java 1️⃣  this Variable ▪ Refers to the current object ▪ Used to resolve variable name conflicts ▪ Helps initialize instance variables 2️⃣ this Method ▪ Calls another method of the same class ▪ Improves readability & clarity 3️⃣ this Constructor ▪ Invokes another constructor in the same class ▪ Enables Constructor Chaining (important concept) ▪ Must be the first statement in constructor 🔹 super Keyword in Java (Used in Inheritance) 1️⃣  super Variable ▪ Refers to parent class variables ▪ Used when parent & child share same field names 2️⃣ super Method ▪ Calls parent class methods ▪ Useful when method is overridden 3️⃣ super Constructor ▪ Invokes parent class constructor ▪ Must be first statement in constructor ▪ If not written, compiler adds it automatically 🔹 final Keyword in Java 1️⃣ final Variable ▪ Value cannot be changed once assigned ▪ Used to create constants 2️⃣ final Method ▪ Cannot be overridden ▪ Ensures method behavior remains fixed 3️⃣ final Class ▪ Cannot be inherited ▪ Prevents extension 📌 Key Takeaway ✔️ this → Refers to current object / constructor chaining ✔️ super → Access parent class members ✔️ final → Restricts modification & inheritance Special thanks to Vaibhav Barde Sir for the clear explanations 🚀💻 #CoreJava #JavaLearning #OOP #ThisKeyword #SuperKeyword #FinalKeyword #JavaDeveloper #LearningJourney

🚀 Learning Java OOP — Understanding Object Class in Java Today I explored one of the most important concepts in Java: **Object Class**, the root of the entire class hierarchy. 🔹 Every class in Java directly or indirectly inherits from `Object` class 🔹 It provides common methods available to all objects 🔹 This is why every object in Java gets default behaviors automatically ✅ Important methods in Object Class: • `toString()` → Converts object data into readable text • `equals()` → Compares two objects • `hashCode()` → Generates unique hash value • `getClass()` → Returns runtime class information • `clone()` → Creates duplicate object • `wait()`, `notify()`, `notifyAll()` → Used in multithreading • `finalize()` → Deprecated method 💡 Key Insight: When we print an object reference, Java internally calls `toString()`. That is why overriding `toString()` helps display object data in a meaningful way. 📌 Object class contains **12 methods + 1 constructor**, and it is called the **parent of all Java classes**. #Java #OOP #ObjectClass #Programming #LearningJourney #JavaDeveloper #SoftwareDevelopment

🚀 Java Revision Journey – Day 11 Today I revised the concept of Association (HAS-A Relationship) in Java and understood how objects of one class can be related to objects of another class to build better object-oriented designs. 📝 Association (HAS-A Relationship): Association represents a relationship where one class contains or uses another class as a part of it. Instead of inheritance (IS-A), this relationship focuses on composition of objects, making code more modular and reusable. 📌 HAS-A Relationship: When an object of one class contains an object of another class as its member variable, it forms a HAS-A relationship. This helps in achieving better code reusability and maintainability in applications. 📍Types of Association: In Java, association mainly appears in two forms – Composition and Aggregation, which define the strength of the relationship between objects. 1️⃣ Composition: Composition represents a strong association between objects. The child object cannot exist independently without the parent object. If the parent object is destroyed, the child object is also destroyed. This relationship indicates strong ownership. 2️⃣ Aggregation: Aggregation represents a weaker form of association. The child object can exist independently of the parent object. Even if the parent object is removed, the associated object can still exist. 🔖 Why Association is Important: Association helps in designing flexible and maintainable systems by promoting object collaboration instead of deep inheritance structures. It is widely used in real-world object modeling. 💻 Understanding relationships like Association, Composition, and Aggregation is important for building well-structured object-oriented applications and designing scalable Java systems. Continuing to strengthen my Java fundamentals step by step. #Java #JavaLearning #JavaDeveloper #OOP #BackendDevelopment #Programming #JavaRevisionJourney

🔗Understanding POJO Class in Java one of the most important and widely used concepts is the # 𝙋𝙊𝙅𝙊 (𝙋𝙡𝙖𝙞𝙣 𝙊𝙡𝙙 𝙅𝙖𝙫𝙖 𝙊𝙗𝙟𝙚𝙘𝙩 𝘾𝙡𝙖𝙨𝙨) ->>A POJO is a simple Java class used to represent data without depending on complex frameworks or special restrictions. ->>It focuses on clean design, simplicity, and reusability. ->>Instead of adding unnecessary complexity, POJO classes help developers create structured and maintainable applications. Why POJO Matters!!! POJO classes are the backbone of many enterprise applications and are widely used in frameworks like Spring and Hibernate. They help in: ✔ Organizing data efficiently ✔ Improving code readability ✔ Making applications easier to maintain # Important Points (Easy to Remember) 📌 What is POJO? POJO = Plain Old Java Object A simple Java class used to store data 📌 Key Characteristics *Private variables (fields) *Public getters and setters *Default (no-argument) constructor *Can have parameterized constructors *Does NOT extend or implement special *framework classes 📌 Why Use POJO? @Improves readability @Promotes reusability @Makes debugging easier @Keeps code clean and simple 🌍 Best Real-Time Example 🏫 Student Management System Imagine building a system to store student details. Instead of mixing logic and data, we use a POJO class: Java 👇 public class Student { private int id; private String name; public Student() {} public Student(int id, String name) { this.id = id; this.name = name; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } 💡 Real-Life Understanding Think of a POJO like a student ID card: It only stores information (ID, Name) It doesn’t perform complex operations It’s simple, clean, and easy to use TAP Academy #Java #OOP #Programming #JavaDeveloper #Coding #SoftwareDevelopment #LearnJava

🚀 Mastering Core Java | Day 13 📘 Topic: Multithreading in Java Today’s learning focused on Multithreading, an important concept in Java that allows programs to perform multiple tasks simultaneously, improving performance and responsiveness. 🔹 What is a Thread? A thread is a lightweight unit of execution within a program. Key Points: Represents a single path of execution Shares resources like memory Enables concurrent task processing 🔹 What is Multithreading? Multithreading is the process of running multiple threads at the same time within a program. Benefits: ✔ Better CPU utilization ✔ Faster task execution ✔ Improved application responsiveness ✔ Efficient resource sharing 🔹 Java Thread Lifecycle A thread goes through several states during execution: 1️⃣ New – Thread is created 2️⃣ Runnable – Ready to run and waiting for CPU 3️⃣ Running – Thread is executing 4️⃣ Waiting / Blocked – Waiting for resources or other threads 5️⃣ Terminated – Execution completed 🔹 Ways to Create Threads in Java 1️⃣ Extending the Thread Class class MyThread extends Thread { public void run() { System.out.println("Thread is running"); } } 2️⃣ Implementing the Runnable Interface class MyRunnable implements Runnable { public void run() { System.out.println("Thread is running"); } } 💡 Key Takeaway: Multithreading helps build efficient, high‑performance, and responsive applications, especially when handling multiple tasks at the same time. Vaibhav Barde sir Grateful for the continuous learning and guidance that helps strengthen my Core Java fundamentals step by step. #CoreJava #Multithreading #JavaDeveloper #JavaLearning #Day13 #Programming #SoftwareDevelopment #LearningJourney 🚀

DAY 30: CORE JAVA 🚀 Understanding "this()" vs "super()" in Java – A Quick Guide! While working with constructors in Java, two important calls often come into play: "this()" and "super()". Though they may seem similar, they serve very different purposes. 🔹 "this()" Call - Used to achieve constructor chaining within the same class. - Helps reuse constructors in a clean and efficient way. - It is optional and depends on the programmer’s need. 🔹 "super()" Call - Used to achieve constructor chaining between parent and child classes. - It is automatically invoked by Java (default behavior). - Always placed on the first line of the child class constructor. ⚠️ Important Rule 👉 "this()" and "super()" cannot be used together in the same constructor, as both must be the first statement. 💡 Key Insight Subclass variables always have higher priority than superclass variables. To access parent class variables when both have the same name, we use "super". 📌 Mastering these concepts is essential for writing clean and efficient code using inheritance in Java. TAP Academy #Java #OOP #Programming #CodingTips #SoftwareDevelopment