🚀 My First Steps in Java: Hello World, Java Structure & Arithmetic Operations

By Abhi Yadav — documenting my journey into Java, one concept at a time.

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👋 Getting Started with Java

I've officially started learning Java, and like every developer's first milestone, I began with the classic:

javaCopy codeSystem.out.println("Hello World");

It may look simple, but this one-liner holds the key to understanding how Java handles syntax, structure, and output. Let me walk you through everything I’ve learned so far — with real code and notes.

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📦 Step 1: My First Java Program

File Name: Hello.java

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

✅ What’s happening here?

• public class Hello → This is the class declaration. The filename and class name must match.

• public static void main(String[] args) → This is the entry point of every Java program.

• System.out.println() → Prints text to the console.

💡 Output:

nginxCopy codeHello World

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🧱 Step 2: Java Structure and Comments

File Name: hello-2.java

This second file taught me the structure of a Java program and how to use comments.

javaCopy codepublic class HelloStructure {
  public static void main(String[] args) {

    // Single-line comment

    /*
     Multi-line comments help you explain
     parts of code in detail
    */

    System.out.println("Learning Java Structure");
  }
}

🧠 Key Concepts:

• Single-line comments: Start with //

• Multi-line comments: Begin with /* and end with */

• Every Java program must have a class, and the execution always starts from the main() method.

🖨 Output:

vbnetCopy codeLearning Java Structure

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➗ Step 3: Arithmetic Operators in Java

File Name: airthmetic_operator.java

This is where I dove into math operations, augmented assignments, and even order of operations (PEMDAS style 😄).

javaCopy codepublic class airthmetic_operator {
  public static void main(String[] args) {

    int x = 10;
    int y = 2;
    int z;

    z = x / y;
    System.out.println(z); // Output: 5

You can also try other operators like:

javaCopy code// z = x + y;
// z = x - y;
// z = x * y;
// z = x % y;

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🧮 Augmented Assignment Operators

Java supports shorthand like:

javaCopy codex += y; // same as x = x + y;
x -= y;
x *= y;
x /= y;
x %= y;

System.out.println(x);

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📈 Increment & Decrement

javaCopy codeint c = 1;
c++;   // increment
c--;   // decrement

System.out.println(c);  // Output: 1 (increment then decrement)

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🧮 Order of Operations (PEMDAS in action!)

javaCopy codedouble result = 3 + 4 * (7 - 5) / 2.0;
System.out.println(result);  // Output: 7.0

Java respects parentheses → exponents → multiplication/division → addition/subtraction just like math.

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➕ Final Practice

javaCopy codeint a = 5;
int b = 10;
int d = 15;

int num = a + b + d;
System.out.println("Addition: " + num); // 30

int num2 = (d - a) - b;
System.out.println("num = " + num2); // 0

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💭 What I’ve Learned So Far

✅ How to write and run my first Java program
✅ Java class structure, main method, and syntax
✅ Using comments for clarity
✅ Arithmetic operations and augmented assignments
✅ Increment/decrement operators
✅ How Java handles operator precedence

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📌 What’s Next?

In my next post, I’ll cover:

• if-else conditions

• Loops (for, while)

• And maybe a mini project to test what I’ve learned 🔥

If you're just starting Java too →let’s connect!
Leave a comment or suggestion if you're on the same journey 💬

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🧠 Blog by Abhi Yadav
🎯 Learning Java. Building in public.
📍 Follow me on X (Twitter)

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