Character type in Rust - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a character variable with the letter 'a'.

Rust

let letter: char = '[1]';

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

A'a'

B'ab'

Ca

D"a"

Attempts:

3 left

💡 Hint

Common Mistakes

Using double quotes instead of single quotes.

Not using quotes at all.

Using more than one character inside quotes.

In Rust, a character is declared using single quotes around a single character, like 'a'.

2fill in blank

medium

Complete the code to print the Unicode code point of the character 'Z'.

Rust

let ch: char = 'Z';
println!("{}", ch [1] u32);

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Ato_digit

Bto_ascii_uppercase

Cto_string

Das

Attempts:

3 left

💡 Hint

Common Mistakes

Using to_digit without an argument.

Trying to call a method that doesn't exist for char.

Using string methods instead of char methods.

To get the Unicode code point of a character like 'Z', cast it to u32 using as u32.

3fill in blank

hard

Fix the error in the code to check if a character is a digit.

Rust

let c = '5';
if c.[1]() {
    println!("It's a digit!");
}

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Ais_alphanumeric

Bis_digit

Cis_numeric

Dis_alphabetic

Attempts:

3 left

💡 Hint

Common Mistakes

Using is_digit() without arguments (it requires a radix).

Using is_alphabetic() which checks for letters.

The correct method to check if a character is a digit is is_numeric() in Rust.

4fill in blank

hard

Fill both blanks to create a map from characters to their uppercase versions for letters only.

Rust

let letters = ['a', 'b', 'c', '1'];
let uppercase_map: std::collections::HashMap<char, char> = letters.iter()
    .filter(|&&c| c.[1]())
    .map(|&c| (c, c.[2]()))
    .collect();

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Ais_alphabetic

Bto_ascii_uppercase

Cis_numeric

Dto_lowercase

Attempts:

3 left

💡 Hint

Common Mistakes

Filtering numeric characters instead of alphabetic.

Using to_lowercase() instead of uppercase.

Use is_alphabetic() to filter letters, and to_ascii_uppercase() to convert them to uppercase.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps characters to their Unicode code points if they are digits.

Rust

let chars = ['a', '3', '7', 'b'];
let digit_map: std::collections::HashMap<char, u32> = chars.iter()
    .filter(|&&c| c.[1]())
    .map(|&c| (c, c [2] [3]))
    .collect();

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

Ais_numeric

Bas

Cu32

Dis_alphabetic

Attempts:

3 left

💡 Hint

Common Mistakes

Using is_alphabetic() instead of is_numeric().

Forgetting to cast the character to u32.

Filter digits with is_numeric(), cast characters to u32 using as to get Unicode code points.