Loop labels in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to label the outer loop correctly.

Rust

fn main() {
    'outer: for i in 1..=3 {
        for j in 1..=3 {
            if i == 2 && j == 2 {
                break [1];
            }
            println!("i = {}, j = {}", i, j);
        }
    }
}

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

A'label

B'inner

C'loop

D'outer

Attempts:

3 left

💡 Hint

Common Mistakes

Using a label that is not defined.

Omitting the apostrophe in the label name.

The label 'outer is used to break out of the outer loop from inside the inner loop.

2fill in blank

medium

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

Rust

fn main() {
    'outer: for i in 1..=3 {
        for j in 1..=3 {
            if j == 2 {
                continue [1];
            }
            println!("i = {}, j = {}", i, j);
        }
    }
}

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

A'inner

B'loop

C'outer

D'label

Attempts:

3 left

💡 Hint

Common Mistakes

Using continue without a label inside nested loops.

Using a label that does not exist.

Using continue with the 'outer label skips to the next iteration of the outer loop.

3fill in blank

hard

Fix the error in the code by choosing the correct label to break the outer loop.

Rust

fn main() {
    'start: for x in 1..=5 {
        for y in 1..=5 {
            if x * y > 6 {
                break [1];
            }
            println!("x = {}, y = {}", x, y);
        }
    }
}

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

A'start

B'outer

C'inner

D'loop

Attempts:

3 left

💡 Hint

Common Mistakes

Using a label that is not defined.

Using break without a label inside nested loops.

The label 'start is defined on the outer loop and must be used to break it.

4fill in blank

hard

Fill both blanks to correctly label and break the outer loop.

Rust

fn main() {
    [1] for num in 1..=4 {
        for letter in ['a', 'b', 'c'].iter() {
            if num == 3 {
                break [2];
            }
            println!("{} - {}", num, letter);
        }
    }
}

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

A'outer:

B'inner:

C'outer

D'inner

Attempts:

3 left

💡 Hint

Common Mistakes

Using the label with colon in the break statement.

Mismatching label names between loop and break.

The outer loop is labeled 'outer: and the break uses 'outer to exit it.

5fill in blank

hard

Fill all three blanks to label the loops and continue the outer loop correctly.

Rust

fn main() {
    [1] for i in 1..=3 {
        [2] for j in 1..=3 {
            if i == 2 && j == 1 {
                continue [3];
            }
            println!("i = {}, j = {}", i, j);
        }
    }
}

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

A'outer:

B'inner:

C'outer

D'inner

Attempts:

3 left

💡 Hint

Common Mistakes

Using the inner loop label in continue instead of the outer.

Including colon in the continue statement.

The outer loop is labeled 'outer:, inner loop 'inner:, and continue uses 'outer to skip to next outer iteration.