Labeled break and continue in Kotlin - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of labeled break in nested loops

What is the output of this Kotlin code using a labeled break?

Kotlin

fun main() {
    outer@ for (i in 1..3) {
        for (j in 1..3) {
            if (i * j > 3) break@outer
            print("$i$j ")
        }
    }
}

A 11 12 13 21

B 11 12 21 22 23

C 11 12 13 21 22 23 31 32 33

D 11 12 21 22 31 32

💡 Hint

The labeled break exits the outer loop when the condition is met.

The code prints pairs i,j until i*j > 3. When i=2 and j=2, 2*2=4 > 3 triggers break@outer, stopping all loops. So output is 11 12 13 21.

❓ Predict Output

intermediate

Output of labeled continue in nested loops

What does this Kotlin code print when using a labeled continue?

Kotlin

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

A 11 21 22 23

B 11 21

C 11 12 13 21 22 23

D 11 13 21 23

💡 Hint

The labeled continue skips to the next iteration of the outer loop when j == 2.

When j == 2, continue@outer skips the rest of the inner loop and moves to next i. So for i=1, j=1 prints 11, j=2 triggers continue@outer skipping j=3. For i=2, j=1 prints 21, j=2 triggers continue@outer skipping j=3. So output is 11 21.

🔧 Debug

advanced

Identify the error with labeled break usage

What error does this Kotlin code produce?

Kotlin

fun main() {
    for (i in 1..3) {
        inner@ for (j in 1..3) {
            if (i == 2) break@outer
            print("$i$j ")
        }
    }
}

A Unresolved reference: outer

B Syntax error: Missing colon after label

C No error, prints 11 12 13 21 22 23 31 32 33

D Runtime exception: Label not found

💡 Hint

Check if the label used in break exists in the code.

The code tries to break@outer, but no label named 'outer' is defined. This causes a compile-time error: Unresolved reference: outer.

📝 Syntax

advanced

Which option correctly uses labeled continue?

Which of these Kotlin code snippets correctly uses labeled continue to skip the current iteration of the outer loop?

A outer@ for (i in 1..2) { for (j in 1..2) { if (j == 2) continue@ else print("$i$j ") } }

B outer@ for (i in 1..2) { for (j in 1..2) { if (j == 2) continue outer else print("$i$j ") } }

C outer@ for (i in 1..2) { for (j in 1..2) { if (j == 2) continue@outer else print("$i$j ") } }

D outer@ for (i in 1..2) { for (j in 1..2) { if (j == 2) continue@inner else print("$i$j ") } }

💡 Hint

Labeled continue syntax requires '@' after the label name.

Option C correctly uses 'continue@outer' to skip the current iteration of the outer loop. Option C misses '@', C uses incomplete label, D uses undefined label 'inner'.

🚀 Application

expert

Count iterations skipped by labeled continue

Given this Kotlin code, what value is printed by println(count)?

Kotlin

fun main() {
    var count = 0
    outer@ for (i in 1..3) {
        for (j in 1..3) {
            count++
            if (i + j == 4) continue@outer
        }
    }
    println(count)
}

A 8

B 7

C 9

D 6

💡 Hint

The continue@outer skips the rest of the inner loop and moves to next i when i+j == 4.

The pairs (i,j) are (1,1),(1,2),(1,3),(2,1),(2,2),(2,3),(3,1),(3,2),(3,3). When i+j==4, pairs are (1,3),(2,2),(3,1). At these points, continue@outer skips remaining inner loop iterations and increments count only for executed count++ statements. Counting executed increments gives 6.