Labeled break and continue in Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a labeled break in Kotlin?

A labeled break in Kotlin is a way to exit a specific loop when you have nested loops. You put a label before the loop and use break with that label to stop that loop.

beginner

How do you define a label for a loop in Kotlin?

You define a label by writing a name followed by the @ symbol before the loop. For example: outer@ for (i in 1..5) { ... }.

intermediate

What does a labeled continue do in Kotlin?

A labeled continue skips the current iteration of the labeled loop and moves to the next iteration of that loop, even if it is an outer loop.

intermediate

Why use labeled break or continue instead of regular break or continue?

Regular break or continue only affect the innermost loop. Labeled versions let you control outer loops directly, which is useful when you have nested loops and want to jump out or skip iterations in outer loops.

intermediate

Example: What will this Kotlin code print?

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

It will print: (1,1) (1,2) (1,3) (2,1) Because when i=2 and j=2, the labeled break exits the outer loop before printing (2,2).

What does the label in Kotlin loops look like?

A A name followed by @ before the loop

B A name followed by # before the loop

C A name inside parentheses after the loop

D A name after the loop with a colon

Labels are defined by writing a name followed by @ before the loop, like label@ for (...) { ... }.

What happens when you use break@label inside nested loops?

A It breaks only the innermost loop

B It causes a syntax error

C It continues the innermost loop

D It breaks out of the loop with the given label

break@label exits the loop that has the matching label.

Which statement is true about labeled continue in Kotlin?

A It restarts the program

B It breaks out of the labeled loop

C It skips to the next iteration of the labeled loop

D It only works with single loops

Labeled continue skips the current iteration of the labeled loop and moves to its next iteration.

Why might you use a labeled break instead of a regular break?

A To exit an outer loop from inside an inner loop

B To exit only the innermost loop

C To skip the rest of the current iteration

D To pause the loop

Labeled break lets you exit an outer loop directly from inside nested loops.

What will happen if you use a label that does not exist with break or continue?

A It breaks the innermost loop

B Compilation error

C It continues the innermost loop

D It ignores the label and runs normally

Using a non-existent label causes a compilation error in Kotlin.

Explain how labeled break works in Kotlin and give a simple example.

Think about how to stop an outer loop from inside an inner loop.

Describe the difference between regular continue and labeled continue in Kotlin.

Consider what happens when you want to skip iterations in outer loops.