Kotlin Conditional Statements: The Decision Makers of Your Code! 🧠🚦

Imagine you're playing a video game 🎮, and you need to decide:

• If your health is low, drink a potion.
• If an enemy attacks, defend or fight.
• If you find treasure, collect it!

Just like in games, your Kotlin programs also need to make decisions based on conditions. This is where conditional statements (if-else and when) come in! 🚀

In this blog, we’ll dive deep into Kotlin’s conditional statements, their types, features, and examples, and how they make your code smarter! 🏆

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1️⃣ What Are Conditional Statements? 🤔

A conditional statement helps your code make decisions based on conditions.

💡 Think of it like this:

• "If it's raining, take an umbrella." ☔
• "If it's sunny, wear sunglasses." 🕶️

In Kotlin, we use:
✅ if-else → When we have two or more possible conditions.
✅ when → When we have multiple options (like a switch case).

Let’s explore both in detail! 🧐

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2️⃣ if-else: The Basic Decision Maker 🏗️

🔹 Syntax of if-else

if (condition) {
    // Code runs if condition is true
} else {
    // Code runs if condition is false
}

🔹 Example: Checking Age for Voting 🗳️

val age = 18

if (age >= 18) {
    println("You can vote! ✅")
} else {
    println("Sorry, you are too young to vote. ❌")
}

🔹 If age is 18 or more, it prints ✅.
🔹 Otherwise, it prints ❌.

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3️⃣ if-else if-else: Multiple Conditions 🔄

What if there are more than two possibilities? Use else if!

🔹 Example: Grading System 🎓

val marks = 85

if (marks >= 90) {
    println("Grade: A 🎯")
} else if (marks >= 75) {
    println("Grade: B ✅")
} else if (marks >= 50) {
    println("Grade: C ⚠️")
} else {
    println("Grade: F ❌")
}

📌 How It Works?

• If marks ≥ 90, print "Grade A".
• Else if marks ≥ 75, print "Grade B".
• Else if marks ≥ 50, print "Grade C".
• Else, print "Grade F".

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4️⃣ if as an Expression (Returning Values) 🎯

Kotlin allows if as an expression, meaning it can return a value! 🚀

🔹 Example: Finding the Maximum of Two Numbers 🏆

val a = 10
val b = 20

val max = if (a > b) a else b
println("The maximum value is $max")  // Output: The maximum value is 20

💡 No need for {} if it’s a single expression!

• If a > b, max = a
• Otherwise, max = b

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5️⃣ when: The Smarter Switch Case! 🚦

Instead of writing multiple if-else if, Kotlin provides when, which is more readable and powerful!

🔹 Syntax of when

when (value) {
    case1 -> // Code
    case2 -> // Code
    else -> // Default case
}

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6️⃣ when with Constants 📌

🔹 Example: Checking the Day of the Week 📅

val day = 3

when (day) {
    1 -> println("Monday")
    2 -> println("Tuesday")
    3 -> println("Wednesday")  // ✅ Matches this case
    4 -> println("Thursday")
    else -> println("Invalid day")
}

Output: Wednesday ✅

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7️⃣ when with Ranges & Multiple Values 🎯

🔹 Example: Categorizing Age Groups 👶🧑👴

val age = 25

when (age) {
    in 0..12 -> println("Child 👶")
    in 13..19 -> println("Teenager 🧑")
    in 20..59 -> println("Adult 💼")
    else -> println("Senior Citizen 👴")
}

💡 How It Works?

• in 0..12 → If age is between 0-12, print "Child".
• in 13..19 → If age is between 13-19, print "Teenager".
• in 20..59 → If age is between 20-59, print "Adult".
• else → Anything outside these ranges prints "Senior Citizen".

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8️⃣ when as an Expression (Returning Values) 🔥

Just like if, when can return a value!

🔹 Example: Finding the Type of an Object 🧐

fun checkType(obj: Any): String {
    return when (obj) {
        is String -> "It's a String 📜"
        is Int -> "It's an Integer 🔢"
        is Boolean -> "It's a Boolean ⚡"
        else -> "Unknown type 🤷"
    }
}

println(checkType(42))  // Output: It's an Integer 🔢

🔹 Using is to check types is a powerful Kotlin feature! 🚀

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9️⃣ when with Functions and Enum Classes 🎨

🔹 Example: Using when with Enums

enum class TrafficLight { RED, YELLOW, GREEN }

fun action(light: TrafficLight) {
    when (light) {
        TrafficLight.RED -> println("Stop 🚦")
        TrafficLight.YELLOW -> println("Get Ready ⏳")
        TrafficLight.GREEN -> println("Go! 🏁")
    }
}

action(TrafficLight.GREEN)  // Output: Go! 🏁

✅ Perfect for handling multiple fixed values!

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🔟 if vs when: When to Use What? 🤔

Feature	if-else	when
Best for	Simple conditions	Multiple conditions
Readability	Less readable for many cases	More readable
Expression?	Yes	Yes
Handles ranges?	Yes	Yes (better)
Works with Enums & Types?	No	Yes ✅

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🔟 Conclusion: Kotlin Makes Decisions Smartly! 🚀

🔹 Use if-else when handling simple conditions.
🔹 Use when when checking multiple values (it’s more readable).
🔹 Use expressions (if and when) to return values.
🔹 Leverage when with ranges, types, and enums for cleaner code.

Now that you know how Kotlin makes decisions, go ahead and try some conditional magic in your code! 🪄✨

💬 Which one do you prefer: if-else or when? Let me know in the comments! ⬇️😊