Kotlin Break / Continue

Control Flow Statements

for (i in 1..10) {
    if (i == 5) break
    println(i)
}

for (i in 1..5) {
    if (i == 3) continue
    println(i) // Skips 3
}

outer@ for (i in 1..3) {
    for (j in 1..3) {
        if (j == 2) break@outer
    }
}

fun search(list: List) {
    for (item in list) {
        if (item == target) return
    }
}

🔹 Break Statement

Exit the loop when a condition is met:

fun main() {
    // Find first number divisible by 7
    println("Finding first number divisible by 7:")
    for (i in 1..50) {
        if (i % 7 == 0) {
            println("Found it! $i is divisible by 7")
            break // Exit the loop
        }
        println("Checking $i...")
    }
    
    // Search in a list
    val fruits = listOf("apple", "banana", "orange", "grape", "kiwi")
    val searchFor = "orange"
    
    println("\nSearching for '$searchFor':")
    for ((index, fruit) in fruits.withIndex()) {
        if (fruit == searchFor) {
            println("✅ Found '$searchFor' at position $index!")
            break
        }
        println("❌ '$fruit' is not what we're looking for")
    }
}

🔹 Continue Statement

Skip current iteration and continue with the next:

fun main() {
    // Print only even numbers
    println("Even numbers from 1 to 10:")
    for (i in 1..10) {
        if (i % 2 != 0) {
            continue // Skip odd numbers
        }
        println("Even: $i")
    }
    
    // Process valid data only
    val data = listOf("apple", "", "banana", "   ", "orange", "grape")
    
    println("\nProcessing valid data:")
    for ((index, item) in data.withIndex()) {
        if (item.isBlank()) {
            println("Skipping empty item at index $index")
            continue
        }
        
        val processed = item.trim().uppercase()
        println("Processed: '$item' → '$processed'")
    }
}

🔹 Nested Loops with Labels

Control which loop to break or continue:

fun main() {
    // Without labels - only breaks inner loop
    println("Without labels:")
    for (i in 1..3) {
        println("Outer loop: $i")
        for (j in 1..3) {
            if (j == 2) {
                println("  Breaking inner loop at j=$j")
                break
            }
            println("  Inner loop: $j")
        }
    }
    
    // With labels - can break outer loop
    println("\nWith labels:")
    outer@ for (i in 1..3) {
        println("Outer loop: $i")
        for (j in 1..3) {
            if (i == 2 && j == 2) {
                println("  Breaking outer loop at i=$i, j=$j")
                break@outer
            }
            println("  Inner loop: i=$i, j=$j")
        }
    }
    
    println("Program continues...")
}

🔹 Practical Examples

Real-world usage scenarios:

fun main() {
    // Password validation with attempts limit
    val correctPassword = "secret123"
    val maxAttempts = 3
    var attempts = 0
    
    while (attempts < maxAttempts) {
        attempts++
        
        // Simulating user input
        val password = when (attempts) {
            1 -> "wrong"
            2 -> "incorrect"
            3 -> "secret123"
            else -> ""
        }
        
        println("Attempt $attempts: Entered '$password'")
        
        if (password == correctPassword) {
            println("✅ Access granted!")
            break // Exit the loop on success
        }
        
        if (attempts == maxAttempts) {
            println("🔒 Account locked after $maxAttempts failed attempts!")
            break
        }
        
        println("❌ Wrong password, try again!")
    }
    
    // Processing numbers with conditions
    println("\nProcessing numbers 1-15:")
    for (num in 1..15) {
        // Skip multiples of 3
        if (num % 3 == 0) {
            println("Skipping $num (multiple of 3)")
            continue
        }
        
        // Stop at first number greater than 12
        if (num > 12) {
            println("Stopping at $num (greater than 12)")
            break
        }
        
        println("Processing: $num")
    }
}

🔹 Return in Loops

Exit from functions using return:

fun findFirstEven(numbers: List): Int? {
    println("Searching for first even number...")
    
    for (num in numbers) {
        println("Checking $num")
        
        if (num % 2 == 0) {
            println("Found even number: $num")
            return num // Exit function immediately
        }
    }
    
    println("No even number found")
    return null
}

fun processItems(items: List) {
    println("Processing items:")
    
    for (item in items) {
        if (item == "STOP") {
            println("Stop command received, ending processing")
            return // Exit function
        }
        
        if (item.isBlank()) {
            println("Skipping empty item")
            continue
        }
        
        println("Processing: $item")
    }
    
    println("All items processed")
}

fun main() {
    val numbers = listOf(1, 3, 5, 8, 9, 10)
    val result = findFirstEven(numbers)
    println("Result: $result\n")
    
    val items = listOf("apple", "banana", "", "STOP", "orange")
    processItems(items)
}