Kotlin break and continue

Welcome to The Coding College! In this tutorial, we’ll dive deep into the break and continue statements in Kotlin. These control flow statements are essential for managing loops effectively and making your code more efficient.

What Are break and continue in Kotlin?

  • break Statement: Used to terminate the nearest enclosing loop immediately.
  • continue Statement: Skips the current iteration of the loop and moves to the next one.

The break Statement

The break statement is used to exit a loop when a specific condition is met, skipping all remaining iterations.

Syntax:

break

Example: Exiting a Loop with break

fun main() {
    for (i in 1..10) {
        if (i == 5) {
            println("Breaking the loop at i = $i")
            break
        }
        println("i = $i")
    }
}

Output:

i = 1  
i = 2  
i = 3  
i = 4  
Breaking the loop at i = 5

The continue Statement

The continue statement skips the current iteration and proceeds with the next iteration of the loop.

Syntax:

continue

Example: Skipping an Iteration with continue

fun main() {
    for (i in 1..5) {
        if (i == 3) {
            println("Skipping i = $i")
            continue
        }
        println("i = $i")
    }
}

Output:

i = 1  
i = 2  
Skipping i = 3  
i = 4  
i = 5

Using break and continue in While Loops

These statements work seamlessly with while and do...while loops.

Example: break in a While Loop

fun main() {
    var num = 1
    while (num <= 10) {
        if (num == 6) {
            println("Breaking the loop at num = $num")
            break
        }
        println("num = $num")
        num++
    }
}

Output:

num = 1  
num = 2  
num = 3  
num = 4  
num = 5  
Breaking the loop at num = 6

Example: continue in a While Loop

fun main() {
    var num = 0
    while (num < 5) {
        num++
        if (num == 3) {
            println("Skipping num = $num")
            continue
        }
        println("num = $num")
    }
}

Output:

num = 1  
num = 2  
Skipping num = 3  
num = 4  
num = 5

Labels with break and continue

Kotlin allows you to use labels with break and continue to specify which loop to control, especially in nested loops.

Example: Labeled break

fun main() {
    outer@ for (i in 1..3) {
        for (j in 1..3) {
            if (i == 2 && j == 2) {
                println("Breaking outer loop at i=$i, j=$j")
                break@outer
            }
            println("i=$i, j=$j")
        }
    }
}

Output:

i=1, j=1  
i=1, j=2  
i=1, j=3  
i=2, j=1  
Breaking outer loop at i=2, j=2

Example: Labeled continue

fun main() {
    outer@ for (i in 1..3) {
        for (j in 1..3) {
            if (i == 2 && j == 2) {
                println("Skipping i=$i, j=$j")
                continue@outer
            }
            println("i=$i, j=$j")
        }
    }
}

Output:

i=1, j=1  
i=1, j=2  
i=1, j=3  
i=2, j=1  
Skipping i=2, j=2  
i=3, j=1  
i=3, j=2  
i=3, j=3

Practical Uses of break and continue

Example: Searching for a Value in a List

fun main() {
    val numbers = listOf(10, 20, 30, 40, 50)
    for (num in numbers) {
        if (num == 30) {
            println("Found $num. Breaking the loop.")
            break
        }
        println("Checking $num")
    }
}

Example: Skipping Specific Values

fun main() {
    val numbers = 1..10
    for (num in numbers) {
        if (num % 2 == 0) {
            continue
        }
        println("Odd number: $num")
    }
}

Output:

Odd number: 1  
Odd number: 3  
Odd number: 5  
Odd number: 7  
Odd number: 9

Best Practices

  1. Use Labels Judiciously: Labels can make code harder to read if overused.
  2. Avoid Overusing break and continue: Use them only when necessary to enhance code clarity.
  3. Handle Infinite Loops Carefully: Ensure break is used appropriately in loops with potentially endless iterations.

Learn More on The Coding College

By understanding break and continue, you can write cleaner and more efficient Kotlin programs. Explore more Kotlin tutorials and programming concepts on The Coding College to master your coding skills.

Conclusion

The break and continue statements are powerful tools in Kotlin for controlling loops effectively. Whether you’re terminating a loop or skipping specific iterations, these statements provide flexibility and precision.

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