Ajay Dabade - Ajay Dabade | Python & Java Learning Notes

🚀 StringBuilder in Java — Complete Detailed Guide

Introduction In Java, strings are used everywhere — for messages, input handling, formatting, file processing, and much more ☕ But there is one important thing many beginners don’t realize: 👉 String objects in Java are immutable.…

Java Basics

🚀 Wrapper Classes in Java — Complete Detailed Guide

Introduction In Java, everything is object-oriented — but primitive data types like int, double, char, and boolean are not objects ☕ This creates a problem. What if we want to: Store numbers inside a collection like…

OOP in Java

🚀 100 MCQs on Java Basics and Basic OOP (Exam Preparation)

1️⃣ Java is a ______ programming language. A) Low-levelB) Object-orientedC) Machine languageD) Assembly ✅ Answer: B 2️⃣ Which component executes Java bytecode? A) JDKB) JREC) JVMD) Compiler ✅ Answer: C 3️⃣ JDK stands for: A) Java…

Revision and Practice

🚀 50 Important Questions & Answers on Java Basics and Basic OOP (Without Inheritance)

A strong foundation in Java fundamentals is essential before moving into advanced topics like inheritance, polymorphism, and multithreading ☕ This article contains 50 carefully structured questions and answers divided into two major sections: 🟢 Section 1:…

Java Basics

🚀 Java Standard Libraries — Core Classes Every Java Developer Must Know

When learning Java, writing logic is important — but knowing how to use Java’s built-in libraries is equally important ☕ Java provides a massive collection of pre-written classes and packages called the Java Standard Library. These…

OOP in Java

10-🔐 Access Modifiers in Java — Complete Guide (private, default, protected, public)

Introduction In Java, writing code is not just about making it work — it is about making it secure, structured, and maintainable ☕ Imagine a situation where every variable in your program is accessible from anywhere.Anyone…

OOP in Java

9-🚀 Nested Classes and Inner Classes in Java

In Java, classes are usually defined separately.But sometimes, it makes logical sense to define a class inside another class 🧩 This concept is called Nested Classes. Nested classes improve: Code organization 📦 Logical grouping 🧠 Encapsulation…

OOP in Java

Java Practice MCQs – Missing Code (Constructors)

✅ Question 1 class Student { String name; int age; Student(String n, int a) { name = n; age = a; } void display() { System.out.println(name + " " + age); } } public class Main…

OOP in Java

Java Practice MCQs – Missing Code Line (OOP Basics)

✅ Question 1 class Student { String name; int marks; void setData(String n, int m) { name = n; marks = m; } void display() { System.out.println(name + " " + marks); } } public class…

OOP in Java

8-Understanding the static Keyword in Java

Introduction In Java, most things revolve around objects ☕But sometimes, certain members belong not to objects, but to the class itself. That is where the static keyword comes into play. The static keyword is one of…