char

Goal of This Episode

Meet the char type — the type for holding “a single character.”

Main Text

We’ve used strings before (text wrapped in double quotes "). Today let’s meet a smaller unit — the character (char).

What Is a char?

A char is one character. Note: “one,” not a string of them.

fn main() {
    let c = 'A';
    let c2 = '你';
    let c3 = '🦀';

    println!("{}", c);
    println!("{}", c2);
    println!("{}", c3);
}

Single Quotes vs Double Quotes

This matters:

• Single quotes ' → char; holds exactly one character.
• Double quotes " → a string; can hold many characters.

fn main() {
    let c = 'A';     // char, one character
    let s = "Hello"; // string, five characters
}

If you put more than one character inside single quotes, Rust reports an error:

fn main() {
    let c = 'AB'; // ❌ Error! A char can hold only one character
}

Unicode

Rust’s char supports Unicode, so it’s not just English letters — Chinese, Japanese, even emoji all work:

fn main() {
    let letter = 'R';
    let chinese = '美';
    let japanese = 'の';
    let emoji = '😊';

    println!("{} {} {} {}", letter, chinese, japanese, emoji);
}

Each of these is a legal char.

Type Annotation

If you want to annotate the type explicitly:

fn main() {
    let c: char = 'Z';
    println!("{}", c);
}

Usually there’s no need, though — Rust sees single quotes and knows it’s a char.

Recap

• char is the “one character” type, wrapped in single quotes: 'A', '你', '🦀'.
• It supports Unicode: Chinese, Japanese, and emoji are all legal chars.
• Single quote ' = char (one character); double quote " = string (a sequence of characters). Don’t mix them up.