How to Use Continue in Kotlin: Simple Guide with Examples

In Kotlin, the continue statement is used inside loops to skip the current iteration and move to the next one immediately. It helps control loop flow by ignoring the remaining code in the loop body for that iteration.

Syntax

The continue statement is used inside loops like for, while, or do-while. When Kotlin encounters continue, it skips the rest of the current loop iteration and jumps to the next one.

Optionally, you can use a label with continue to specify which outer loop to continue when nested loops are involved.

kotlin

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

// Using label with continue
outer@ for (i in 1..3) {
    for (j in 1..3) {
        if (j == 2) continue@outer
        println("i = $i, j = $j")
    }
}

Output

1
2
4
5
i = 1, j = 1
i = 2, j = 1
i = 3, j = 1

Example

This example shows how continue skips printing the number 3 in a loop from 1 to 5. It also demonstrates using a label to skip to the next iteration of an outer loop when a condition in the inner loop is met.

kotlin

fun main() {
    for (number in 1..5) {
        if (number == 3) {
            continue // Skip number 3
        }
        println("Number: $number")
    }

    println("--- Nested loops with label ---")

    outer@ for (i in 1..3) {
        for (j in 1..3) {
            if (j == 2) {
                continue@outer // Skip to next i when j is 2
            }
            println("i = $i, j = $j")
        }
    }
}

Output

Number: 1
Number: 2
Number: 4
Number: 5
--- Nested loops with label ---
i = 1, j = 1
i = 2, j = 1
i = 3, j = 1

Common Pitfalls

A common mistake is using continue outside of loops, which causes a compilation error because continue only works inside loops. Another pitfall is forgetting to use labels in nested loops, which can lead to unexpected behavior by continuing the wrong loop.

Also, overusing continue can make code harder to read, so use it sparingly for clarity.

kotlin

fun main() {
    // Wrong: continue outside loop
    // continue // This will cause a compile error

    // Nested loops without label
    for (i in 1..2) {
        for (j in 1..2) {
            if (j == 2) {
                continue // Only continues inner loop
            }
            println("i=$i, j=$j")
        }
    }

    println("--- Correct with label ---")

    outer@ for (i in 1..2) {
        for (j in 1..2) {
            if (j == 2) {
                continue@outer // Correctly continues outer loop
            }
            println("i=$i, j=$j")
        }
    }
}

Output

i=1, j=1
i=2, j=1
--- Correct with label ---
i=1, j=1

Quick Reference

Usage	Description
continue	Skips the rest of the current loop iteration and moves to the next iteration.
continue@label	Skips to the next iteration of the loop marked by the specified label.
Allowed loops	for, while, do-while
Not allowed	Outside loops (causes compile error)

Key Takeaways

Use continue inside loops to skip the current iteration and proceed to the next.

In nested loops, use labeled continue@label to specify which loop to continue.

Do not use continue outside loops; it will cause a compile error.

Overusing continue can reduce code readability, so use it carefully.

Remember continue only skips the rest of the current iteration, not the entire loop.