Why pattern matching is needed in Rust - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print a message based on the number using pattern matching.

Rust

let number = 1;
match number {
    [1] => println!("One"),
    2 => println!("Two"),
    _ => println!("Other"),
}

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

A4

B3

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number that does not match the variable value.

Forgetting the underscore (_) pattern for other cases.

The pattern 1 matches when number is 1, so the message "One" is printed.

2fill in blank

medium

Complete the code to match a character and print its type.

Rust

let ch = 'a';
match ch {
    [1] => println!("Vowel"),
    'b' | 'c' => println!("Consonant"),
    _ => println!("Other"),
}

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

A'o'

B'a'

C'd'

D'e'

Attempts:

3 left

💡 Hint

Common Mistakes

Using double quotes instead of single quotes for characters.

Choosing a character not listed in the match arms.

The pattern 'a' matches the character ch when it is 'a', printing "Vowel".

3fill in blank

hard

Fix the error in the match pattern to correctly match the tuple.

Rust

let pair = (0, -2);
match pair {
    ([1], y) if y < 0 => println!("Negative y"),
    _ => println!("Other"),
}

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

A0

Bx

C_

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name instead of a literal for the first element.

Not using a guard condition to check if y is negative.

The pattern (0, y) matches when the first element is 0 and binds the second element to y.

4fill in blank

hard

Fill both blanks to create a pattern that matches a Some variant with a positive number.

Rust

let value = Some(5);
match value {
    Some([1]) if [2] > 0 => println!("Positive number"),
    _ => println!("Other"),
}

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

Ax

Cy

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the pattern and guard.

Using a literal instead of a variable in the pattern.

Using x binds the inner value of Some and checks if it is greater than 0.

5fill in blank

hard

Fill all three blanks to destructure a struct and print its fields.

Rust

struct Point { x: i32, y: i32 }
let p = Point { x: 10, y: 20 };
match p {
    Point { [1]: a, [2]: b } if a < b => println!("x < y"),
    Point { [3]: _, y } => println!("Other case"),
}

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

Ax

By

Dz

Attempts:

3 left

💡 Hint

Common Mistakes

Using a field name that does not exist in the struct.

Using the same variable name for different fields.

The first match arm destructures x and y into a and b. The second arm matches y and ignores x.