Kotlin If Expression: Control Your Flow in 2025

Kotlin If Expression: Control Your Flow in 2025! 🚀

The if expression returns a value and steers your program’s flow. 🌟 It comes in various forms in Kotlin.

• if-else expression 🔍
• if-else if-else ladder expression ⚖️
• nested if expression 🧩

if-else Expression 🔍

The result of an if-else expression can be stored in a variable! 📦

Note: When using if as an expression, else is mandatory. 🚫

fun main(args: Array<String>) {  
    val num1 = 10  
    val num2 = 20  
    val result = if (num1 > num2) {  
        "$num1 is greater than $num2"  
    } else {  
        "$num1 is smaller than $num2"  
    }  
    println(result)  // 10 is smaller than 20 📉
}

Using if-else in a single-line expression mimics Java’s ternary operator—no ternary exists in Kotlin! ⚡

Note: You can skip curly braces {} for single-statement if blocks. 🌈

fun main(args: Array<String>) {  
    val num1 = 10  
    val num2 = 20  
    val result = if (num1 > num2) "$num1 is greater than $num2" else "$num1 is smaller than $num2"  
    println(result)  // 10 is smaller than 20 📉
}

Key Features:

• ✅ Returns a value directly to a variable.
• ⚡ Replaces bulky conditionals with concise logic.
• 📏 Works with any comparison (e.g., >=, <=).
• 🔍 Single-line form is super compact.

if-else if-else Ladder Expression ⚖️

fun main(args: Array<String>) {  
    val num = 10  
    val result = if (num > 0) {  
        "$num is positive"  
    } else if (num < 0) {  
        "$num is negative"  
    } else {  
        "$num is zero"  
    }  
    println(result) // 10 is positive 👍
}

Ladder Benefits:

• 📊 Handles multiple conditions in sequence.
• 🔄 Each else if adds a new check.
• ✅ Final else catches all other cases.
• ⚡ Still returns a single value.

Nested if Expression 🧩

fun main(args: Array<String>) {  
    val num1 = 25  
    val num2 = 20  
    val num3 = 30  
    val result = if (num1 > num2) {  
        val max = if (num1 > num3) {  
            num1  
        } else {  
            num3  
        }  
        "body of if " + max  
    } else if (num2 > num3) {  
        "body of else if " + num2  
    } else {  
        "body of else " + num3  
    }  
    println("$result")  // body of if 30 🎉
}

Nested Power:

• 🧩 Layers if statements for deeper logic.
• 🔍 Compares multiple values step-by-step.
• 📈 Finds max or min in nested conditions.
• ⚡ Combines checks into a single result.

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