Didn’t study Java all semester?
This guide will take you from zero → exam-ready → confident pass in a few days.

🎯 HOW TO USE THIS

• Day 1 → Unit 1
• Day 2 → Unit 2
• Day 3 → Unit 3
• Day 4 → Unit 4 + 5
• Day 5 → Revision

👉 Focus on VVI ⭐⭐⭐⭐ topics

🧠 UNIT I — JAVA BASICS

✅ C++ vs Java (VVI ⭐⭐⭐⭐)

Short Para:
Java is platform-independent and secure, while C++ is platform-dependent and faster but less secure.

✅ Java & Internet / WWW

Short Para:
Java is widely used for web development and works well with internet applications using browsers and servers.

✅ Java Environment

📌 Includes:

• JDK (Java Development Kit)
• JRE (Java Runtime Environment)
• JVM (Java Virtual Machine)

✅ JVM (VVI ⭐⭐⭐⭐)

Short Para:
JVM is a virtual machine that runs Java bytecode and makes Java platform-independent.

✅ Java Program Structure

class Main {
    public static void main(String[] args) {
        System.out.println("Hello");
    }
}

✅ Tokens

📌 Smallest unit of Java:

• Keywords
• Identifiers
• Literals
• Operators

✅ Data Types

• int, float, char, boolean

✅ Variables & Constants

• Variable → value changes
• Constant → fixed value (final)

✅ Type Casting

int a = (int) 10.5;

✅ Operators

• Arithmetic → + - *
• Relational → > <
• Logical → && ||
• Assignment → =

✅ Decision Making

if(x > 0) {
    System.out.println("Positive");
}

✅ Loops (VVI ⭐⭐⭐⭐)

for(int i=0; i<5; i++) {
    System.out.println(i);
}

✅ Jump Statements

• break → exit loop
• continue → skip iteration

✅ Labeled Loop

outer:
for(int i=0;i<3;i++){
    for(int j=0;j<3;j++){
        break outer;
    }
}

🧠 UNIT II — OOP IN JAVA (MOST IMPORTANT)

✅ Class & Object (VVI ⭐⭐⭐⭐)

Short Para:
Class is a blueprint, object is its instance.

class Student {
    int age;
}

✅ Constructors

Student() {
    System.out.println("Constructor");
}

✅ Method Overloading

Same method name, different parameters

✅ Static Members

Shared by all objects

✅ Inheritance (VVI ⭐⭐⭐⭐)

class A {}
class B extends A {}

✅ Method Overriding

Child class modifies parent method

✅ Final Keyword

• final variable → constant
• final method → cannot override
• final class → cannot inherit

✅ Abstract Class

Cannot create object

✅ Visibility Control

• public
• private
• protected

🧠 UNIT III — ARRAYS, INTERFACES, PACKAGES

✅ Arrays (VVI ⭐⭐⭐⭐)

int arr[] = {1,2,3};

✅ 2D Array

int arr[][] = {{1,2},{3,4}};

✅ Strings

String s = "Java";

✅ Vector

Dynamic array

✅ Wrapper Classes

Convert primitive → object
Example: Integer, Double

✅ Interfaces (VVI ⭐⭐⭐⭐)

interface A {
    void show();
}

✅ Packages

Used to organize classes

🧠 UNIT IV — THREADS

✅ Thread

Short Para:
Thread is a lightweight process used for multitasking.

✅ Creating Thread

class A extends Thread {
    public void run() {
        System.out.println("Thread");
    }
}

✅ Life Cycle

• New
• Runnable
• Running
• Dead

✅ Synchronization

Used to control multiple threads

✅ Runnable Interface

Alternative way to create thread

🧠 UNIT V — APPLETS

✅ Applet

Short Para:
Applet is a Java program that runs inside a web browser.

✅ Applet vs Application

✅ Applet Life Cycle

• init()
• start()
• stop()
• destroy()

✅ Applet Tag

<applet code="Test.class" width="300" height="300"></applet>

✅ Passing Parameters

Using HTML tag

✅ Getting Input

Using UI elements

🔥 MUST PREPARE (HIGH SCORE)

• C++ vs Java ⭐⭐⭐⭐
• JVM ⭐⭐⭐⭐
• Loops ⭐⭐⭐⭐
• Class & Object ⭐⭐⭐⭐
• Inheritance ⭐⭐⭐⭐
• Interfaces ⭐⭐⭐⭐
• Arrays ⭐⭐⭐⭐
• Threads ⭐⭐⭐⭐
• Applet Life Cycle ⭐⭐⭐⭐

📅 5-DAY PLAN

Day 1 → Unit 1
Day 2 → Unit 2
Day 3 → Unit 3
Day 4 → Unit 4 + 5
Day 5 → Revision

🚀 FINAL MESSAGE

You don’t need full semester study.
You need smart revision + important topics.

👉 Read this 2–3 times
👉 Practice key programs
👉 Go confident