🚦 C++ Conditional Statements: The Traffic Lights of Your Code

Imagine you’re at a crossroads. Left leads to the park, right leads to school, straight goes home. How do you decide? You check conditions!

That’s exactly what conditional statements do in C++. They help your program make decisions, just like you do every day.

🎯 The Big Picture

Think of your code as a train on tracks. Normally, it goes straight. But with conditional statements, you can add switches that send the train down different tracks based on conditions.

graph TD
    A[Start] --> B{Condition?}
    B -->|True| C[Do This]
    B -->|False| D[Do That]
    C --> E[Continue]
    D --> E

🔵 The if Statement

What Is It?

The if statement is the simplest decision maker. It says:

“IF something is true, THEN do this thing.”

Real-Life Example

You’re a kid deciding whether to bring an umbrella:

• IF it’s raining → bring umbrella
• Otherwise → do nothing extra

Code Example

int weather = 1; // 1 means rainy

if (weather == 1) {
    cout << "Bring umbrella!";
}

What happens?

• The computer checks: Is weather equal to 1?
• Yes! So it prints “Bring umbrella!”

The Anatomy

if (condition) {
    // code runs ONLY if
    // condition is true
}

Key Points:

• The condition goes inside ( )
• The action goes inside { }
• If condition is false, the code inside is skipped

🟢 The if-else Statement

What If the Condition Is False?

Sometimes you want to do something else when the condition fails. That’s where else comes in!

Real-Life Example

At a theme park ride:

• IF you’re tall enough → you can ride
• ELSE → you must wait outside

Code Example

int height = 130; // in centimeters

if (height >= 140) {
    cout << "Welcome aboard!";
} else {
    cout << "Sorry, too short.";
}

Output: Sorry, too short.

Because 130 is NOT >= 140, the else block runs.

The Flow

graph TD
    A[Check Height] --> B{height >= 140?}
    B -->|Yes| C[Welcome aboard!]
    B -->|No| D[Sorry, too short]

🟡 The else if Ladder

Multiple Choices

What if you have MORE than two options? Use else if to chain conditions!

Real-Life Example

Getting a grade based on score:

• 90+ = A
• 80-89 = B
• 70-79 = C
• Below 70 = Try harder!

Code Example

int score = 85;

if (score >= 90) {
    cout << "Grade: A";
} else if (score >= 80) {
    cout << "Grade: B";
} else if (score >= 70) {
    cout << "Grade: C";
} else {
    cout << "Keep practicing!";
}

Output: Grade: B

Because 85 is not >= 90, but it IS >= 80!

How It Works

The computer checks each condition in order:

1. Is score >= 90? No, skip.
2. Is score >= 80? Yes! Run this block and stop checking.

Important: Once a condition is true, the rest are ignored.

Visual Flow

graph TD
    A[Score: 85] --> B{score >= 90?}
    B -->|No| C{score >= 80?}
    C -->|Yes| D[Grade: B]
    B -->|Yes| E[Grade: A]
    C -->|No| F{score >= 70?}
    F -->|Yes| G[Grade: C]
    F -->|No| H[Keep practicing!]

🔴 The switch Statement

The Menu Selector

Sometimes you have one variable with many exact values to check. switch is perfect for this!

Real-Life Example

A vending machine:

• Press 1 → Get chips
• Press 2 → Get candy
• Press 3 → Get soda
• Any other button → Invalid choice

Code Example

int choice = 2;

switch (choice) {
    case 1:
        cout << "Here's your chips!";
        break;
    case 2:
        cout << "Here's your candy!";
        break;
    case 3:
        cout << "Here's your soda!";
        break;
    default:
        cout << "Invalid choice!";
}

Output: Here's your candy!

The Parts Explained

⚠️ The break is SUPER Important!

Without break, the code falls through to the next case:

int x = 1;

switch (x) {
    case 1:
        cout << "One ";
    case 2:
        cout << "Two ";
    case 3:
        cout << "Three";
        break;
}
// Output: One Two Three

All three print because there’s no break after case 1 and 2!

When to Use Switch vs If-Else

🎮 Putting It All Together

The Game Menu Example

int menu = 2;

switch (menu) {
    case 1:
        cout << "Starting game...";
        break;
    case 2:
        cout << "Loading saved game...";
        break;
    case 3:
        cout << "Goodbye!";
        break;
    default:
        cout << "Pick 1, 2, or 3!";
}

The Weather Advisor

int temp = 25;

if (temp > 30) {
    cout << "It's hot! Drink water.";
} else if (temp > 20) {
    cout << "Nice weather!";
} else if (temp > 10) {
    cout << "Bring a jacket.";
} else {
    cout << "Brrr! Stay warm!";
}

🧠 Quick Summary

💡 Pro Tips

1. Always use { } braces - Even for one line. It prevents bugs!

2. Remember == not =

   • = assigns a value
   • == compares values

3. Don’t forget break in switch - Or your cases will fall through!

4. Order matters in else-if - Check the most specific condition first.

🚀 You’ve Got This!

Conditional statements are like giving your program a brain. It can now think and decide!

• if = “Do this if true”
• else = “Otherwise, do this”
• else if = “Check another condition”
• switch = “Pick from a menu of choices”

Now go build something that makes decisions! 🎉