Match expression deep dive in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to match the number 3 and print a message.

Rust

let number = 3;
match number {
    [1] => println!("Three!"),
    _ => println!("Not three"),
}

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

Anumber

B3

C"3"

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around 3 makes it a string, which won't match the integer.

Using a variable name instead of the literal value.

The match arm must match the value 3 exactly, so use 3.

2fill in blank

medium

Complete the code to match a tuple and print the second element.

Rust

let pair = (5, 10);
match pair {
    ([1], y) => println!("Second is {}", y),
    _ => println!("No match"),
}

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A_

Bx

C5

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable for the first element but printing the wrong variable.

Trying to match the exact value 5 instead of ignoring it.

Using _ ignores the first element, so y is the second element printed.

3fill in blank

hard

Fix the error in the match arm to correctly match a reference to a number.

Rust

let num = &7;
match num {
    [1] => println!("Seven!"),
    _ => println!("Not seven"),
}

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Aref 7

B7

C*7

D&7

Attempts:

3 left

💡 Hint

Common Mistakes

Matching the value 7 directly instead of the reference.

Using *7 which is invalid syntax in patterns.

The variable num is a reference, so the pattern must match &7.

4fill in blank

hard

Fill both blanks to match an enum variant and extract its value.

Rust

enum Color {
    Rgb(u8, u8, u8),
    Cmyk(u8, u8, u8, u8),
}

let color = Color::Rgb(10, 20, 30);
match color {
    Color::[1](r, g, b) => println!("Red: {}, Green: {}, Blue: {}", r, g, b),
    Color::[2](_, _, _, _) => println!("CMYK color"),
}

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ARgb

BCmyk

CRgbColor

DCmykColor

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variant names like RgbColor.

Mixing up the order of variants.

The enum variants are Rgb and Cmyk. Use these exact names to match.

5fill in blank

hard

Fill all three blanks to match a struct and extract fields with pattern matching.

Rust

struct Point {
    x: i32,
    y: i32,
}

let p = Point { x: 0, y: 7 };
match p {
    Point { [1]: 0, [2]: [3] } => println!("On the y axis at {}", y),
    _ => println!("Not on the y axis"),
}

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Ax

By

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping field names or binding the wrong variable.

Using incorrect syntax for struct pattern matching.

Match the field x to 0, bind y to a variable y to print it.