Java If-Else Statements — Make Your Code Think!

🧠 Part 3: If-Else in Java — Make Your Code Think for You

So far, you’ve learned how to store information with variables. Now it’s time to teach your code how to make decisions — like a brain!

🤔 What Is an If-Else Statement?

Imagine this:

If it’s raining, take an umbrella.
Else, wear sunglasses. 😎

This is how real-life decisions work — and Java can do the same!

javaCopyEditif (condition) {
  // do this
} else {
  // do that
}

🧪 Example: Basic If-Else

int age = 18;

if (age >= 18) {
    System.out.println("You can vote!");
} else {
    System.out.println("Sorry, too young to vote.");
}

✅ If the condition is true (age >= 18), it runs the first part
❌ If not, it runs the second part

🧩 How Conditions Work

Conditions are true or false questions. Here are the most common:

🧠 Else If = More Options!

You can chain decisions using else if.

int temp = 30;

if (temp > 30) {
    System.out.println("It's hot!");
} else if (temp >= 15) {
    System.out.println("Nice weather.");
} else {
    System.out.println("Brrr... it's cold.");
}

Java reads them top-down and picks the first one that’s true.

🎯 Real Example: Grading System

int score = 85;

if (score >= 90) {
    System.out.println("Grade: A");
} else if (score >= 80) {
    System.out.println("Grade: B");
} else if (score >= 70) {
    System.out.println("Grade: C");
} else {
    System.out.println("You need to study more!");
}

📌 Try changing the score to see how your program reacts.

🛠 Mini Challenge: Build a Mood Bot

Try writing a program that prints a message based on mood:

String mood = "happy";

if (mood.equals("happy")) {
    System.out.println("Yay! Keep smiling 😊");
} else if (mood.equals("sad")) {
    System.out.println("Sending you good vibes ❤️");
} else {
    System.out.println("Mood not recognized 😐");
}

✅ Tip: Use .equals() for comparing String values.

⚠️ Quick Warnings for Beginners

• Use == for numbers
• Use .equals() for strings
• Always open {} curly braces for blocks
• Conditions must be true or false

🧭 What’s Next? (Part 4 Preview)

Now that your code can think, let’s make it loop! 🔁

In Part 4, we’ll cover:

➡ What is a loop?
➡ How to repeat actions using for and while
➡ Write a program that counts, loops through lists, or creates patterns

🔖 Java If-Else Cheat Sheet

if (condition) {
    // runs if condition is true
} else if (anotherCondition) {
    // runs if previous was false but this is true
} else {
    // runs if all above are false
}