fn main() {
    let a = [1, 2, 3, 4, 5];

    let first = a[0];
    let second = a[1];

    println! ("
        数组 a：{:?}
        数组的第一个元素：{first}
        第二个元素：{second}
        a[0]: {a[0]}
    ", a);
}
