Char Primitives

Character type และ Unicode ใน Rust

Basic Usage

fn main() {
    // ============================================
    // Char literal
    // ============================================

    let c: char = 'A';
    let heart: char = '❤';
    let crab: char = '🦀';
    let thai: char = 'ก';

    println!("Chars: {} {} {} {}", c, heart, crab, thai);

    // ============================================
    // Unicode escape
    // ============================================

    let alpha: char = '\u{03B1}';  // α
    let omega: char = '\u{03C9}';  // ω
    let smiley: char = '\u{1F600}'; // 😀

    println!("Greek: {} {}", alpha, omega);
    println!("Emoji: {}", smiley);

    // ============================================
    // Char is 4 bytes (Unicode scalar value)
    // ============================================

    println!("\nSize of char: {} bytes", std::mem::size_of::<char>());
    println!("Max char: U+{:X}", char::MAX as u32);

    // From integer
    let c = char::from_u32(0x41);
    println!("From 0x41: {:?}", c);

    // Invalid (surrogate)
    let invalid = char::from_u32(0xD800);
    println!("From 0xD800: {:?}", invalid);
}