陣列

fn main() {
    let mut a: [i8; 10] = [42; 10];
    a[5] = 0;
    println!("a: {a:?}");
}

This slide should take about 5 minutes.

A value of the array type [T; N] holds N (a compile-time constant) elements of the same type T. Note that the length of the array is part of its type, which means that [u8; 3] and [u8; 4] are considered two different types. Slices, which have a size determined at runtime, are covered later.
請嘗試存取超出範圍的陣列元素。系統會在執行階段檢查存取陣列的行為。Rust 通常可對這類檢查進行最佳化處理，避免使用不安全的 Rust 執行這些檢查。
我們可以使用常值將值指派給陣列。
The println! macro asks for the debug implementation with the ? format parameter: {} gives the default output, {:?} gives the debug output. Types such as integers and strings implement the default output, but arrays only implement the debug output. This means that we must use debug output here.
加入 # (例如 {a:#?}) 可叫用方便閱讀的「美化排版」格式。

Comprehensive Rust 🦀