Labelled break and continue in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to break out of the outer loop using a label.

Go

OuterLoop:
for i := 0; i < 3; i++ {
    for j := 0; j < 3; j++ {
        if i == 1 && j == 1 {
            [1] OuterLoop
        }
        println(i, j)
    }
}

Drag options to blanks, or click blank then click option'

Acontinue

Bgoto

Cbreak

Dexit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'continue' instead of 'break' to exit the loop.

Forgetting to add the label after 'break'.

In Go, break with a label exits the labeled loop.

2fill in blank

medium

Complete the code to continue the outer loop when a condition is met.

Go

Outer:
for i := 0; i < 3; i++ {
    for j := 0; j < 3; j++ {
        if i == 1 && j == 1 {
            [1] Outer
        }
        println(i, j)
    }
}

Drag options to blanks, or click blank then click option'

Askip

Bbreak

Cgoto

Dcontinue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'break' instead of 'continue' to skip iterations.

Not specifying the label after 'continue'.

Using continue with a label skips to the next iteration of the labeled loop.

3fill in blank

hard

Fix the error by choosing the correct keyword to break the labeled loop.

Go

Loop1:
for x := 0; x < 5; x++ {
    for y := 0; y < 5; y++ {
        if x*y > 6 {
            [1] Loop1
        }
        println(x, y)
    }
}

Drag options to blanks, or click blank then click option'

Abreak

Bcontinue

Cexit

Dgoto

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'continue' to exit the loop causes wrong behavior.

Using 'goto' without proper label placement causes errors.

The break keyword with a label exits the labeled loop correctly.

4fill in blank

hard

Fill both blanks to continue the outer loop and break the inner loop correctly.

Go

OuterLoop:
for i := 0; i < 3; i++ {
    InnerLoop:
    for j := 0; j < 3; j++ {
        if j == 1 {
            [1] OuterLoop
            [2] InnerLoop
        }
        println(i, j)
    }
}

Drag options to blanks, or click blank then click option'

Acontinue

Bbreak

Cgoto

Dskip

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'break' for both blanks causes incorrect loop behavior.

Using 'continue' for both blanks does not exit the inner loop.

continue OuterLoop skips to the next iteration of the outer loop, and break InnerLoop exits the inner loop.

5fill in blank

hard

Fill all three blanks to break the outer loop, continue the inner loop, and break the labeled loop correctly.

Go

Label1:
for a := 0; a < 3; a++ {
    Label2:
    for b := 0; b < 3; b++ {
        if a == 1 && b == 1 {
            [1] Label1
        }
        if b == 0 {
            [2] Label2
        }
        if a == 2 {
            [3] Label1
        }
        println(a, b)
    }
}

Drag options to blanks, or click blank then click option'

Acontinue

Bbreak

Cgoto

Dexit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'goto' or 'exit' which are invalid in this context.

Mixing up which label to use with break or continue.

break Label1 exits the outer loop, continue Label2 skips to the next inner loop iteration, and break Label1 again exits the outer loop.

Practice

1. What is the main purpose of using a labelled break in Go nested loops?

easy

A. To declare a new variable inside the loop

B. To exit from an outer loop directly

C. To restart the entire program

D. To skip the current iteration of the inner loop

Solution

1. Step 1: Understand labelled break usage

   A labelled break lets you exit a specific loop, usually an outer one, directly from inside nested loops.

2. Step 2: Compare with normal break

   Normal break exits only the innermost loop, but labelled break can exit outer loops by specifying the label.

3. Final Answer:

   To exit from an outer loop directly -> Option B

4. Quick Check:

   Labelled break = exit outer loop [OK]

Hint: Labelled break jumps out of outer loops directly [OK]

Common Mistakes:

• Thinking break skips iteration instead of exiting loop
• Confusing labelled break with continue
• Assuming break restarts loops

2. Which of the following is the correct syntax to use a labelled continue in Go?

easy

A. continue labelName

B. continue to labelName

C. continue(labelName)

D. continue; labelName

Solution

1. Step 1: Recall labelled continue syntax

   In Go, to continue a labelled loop, you write continue labelName without parentheses or extra keywords.

2. Step 2: Check other options

   Options A, B, and D use incorrect syntax like extra words, parentheses, or semicolons which are invalid in Go.

3. Final Answer:

   continue labelName -> Option A

4. Quick Check:

   Labelled continue syntax = continue labelName [OK]

Hint: Use 'continue' followed by label name without punctuation [OK]

Common Mistakes:

• Adding parentheses around label
• Using extra words like 'to' or semicolons
• Confusing break and continue syntax

3. What will be the output of the following Go code?

outer:
for i := 1; i <= 3; i++ {
    for j := 1; j <= 3; j++ {
        if i*j > 3 {
            break outer
        }
        fmt.Print(i*j, " ")
    }
}

medium

A. 1 2 3 2

B. 1 2 3 2 4 6 3 6 9

C. 1 2 2 3

D. 1 2 2 3 3

Solution

1. Step 1: Trace the nested loops and condition

   For i=1, j=1 to 3: i*j = 1,2,3 (all ≤ 3), so prints "1 2 3 ". For i=2, j=1: i*j=2 (≤3), prints "2 ". Next j=2: i*j=4 (>3), triggers break outer which exits the outer loop immediately.

2. Step 2: Understand break outer effect

   Since break outer exits both loops, no further printing occurs after i=2, j=2 check.

3. Final Answer:

   1 2 3 2 -> Option A

4. Quick Check:

   Labelled break exits outer loop at i*j>3 [OK]

Hint: Labelled break exits all loops at condition [OK]

Common Mistakes:

• Ignoring labelled break effect and continuing loops
• Confusing break with continue
• Miscomputing i*j values

4. Identify the error in this Go code snippet using labelled continue:

outer:
for i := 0; i < 3; i++ {
    for j := 0; j < 3; j++ {
        if i == j {
            continue
        }
        fmt.Println(i, j)
    }
}

medium

A. continue cannot be used inside nested loops

B. Label 'outer' is not defined before the loops

C. Missing label after continue to specify which loop to continue

D. fmt.Println syntax is incorrect

Solution

1. Step 1: Check labelled continue usage

   The code defines label 'outer' but uses plain continue inside inner loop. To continue the outer loop, it must be continue outer.

2. Step 2: Understand effect of missing label

   Without label, continue only skips current inner loop iteration, not the outer loop. The label is unused, which is likely a mistake.

3. Final Answer:

   Missing label after continue to specify which loop to continue -> Option C

4. Quick Check:

   Labelled continue needs label after continue [OK]

Hint: Use label after continue to affect outer loops [OK]

Common Mistakes:

• Using continue without label when label is defined
• Assuming continue skips outer loop without label
• Confusing label placement

5. Given nested loops labelled outer and inner, how would you skip the rest of the current iteration of the outer loop from inside the inner loop in Go?

hard

A. Use break inner inside the inner loop

B. Use break outer inside the outer loop

C. Use continue inner inside the outer loop

D. Use continue outer inside the inner loop

Solution

1. Step 1: Understand labelled continue behavior

   Using continue outer inside the inner loop skips the rest of the current iteration of the outer loop and moves to the next iteration of the outer loop.

2. Step 2: Differentiate from break and other options

   break inner exits the inner loop, but does not skip outer loop iteration. continue inner affects inner loop only. break outer exits the outer loop entirely.

3. Final Answer:

   Use continue outer inside the inner loop -> Option D

4. Quick Check:

   Labelled continue skips outer loop iteration [OK]

Hint: Use 'continue' with outer label to skip outer iteration [OK]

Common Mistakes:

• Using break instead of continue to skip iteration
• Applying continue to wrong loop label
• Confusing break and continue effects