在循环内访问向量的元素时遇到麻烦

Question

我正在尝试通过println打印向量的元素！循环内。

这是我得到的错误，无法弄清楚我在做什么错。请指教！

error[E0277]: the type `[i32]` cannot be indexed by `i32`
   |
21 |         s = v[outercount];
   |             ^^^^^^^^^^^^^ slice indices are of type `usize` or ranges of `usize`
   |
   = help: the trait `std::slice::SliceIndex<[i32]>` is not implemented for `i32`
   = note: required because of the requirements on the impl of `std::ops::Index<i32>` for `std::vec::Vec<i32>`

let v = vec![1,4,2,4,1,8];
let mut outercount:i32 = 0;
loop {
    outercount += 1;
    s = v[outercount];
    println!("{}", s);
    if outercount == (v.len() - 1) as i32 { break; }
}

Answer 1

如错误消息所提示，索引必须为usize，而不是i32：

let v = vec![1,4,2,4,1,8];
let mut outercount: usize = 0;    // declare outercount as usize instead of i32
loop {
    let s = v[outercount];        // need to declare variable here
    println!("{}", s);
    outercount += 1;
    if outercount == v.len() { break; }
}

Answer 2

我知道这可能实际上对您的代码@Sumchans没有帮助，但是我不得不写一个more idiomatic版本。我希望它可以帮助某人：

fn main() {
   let v = vec![1,4,2,4,1,8];
   v.iter().for_each(|n| println!("{}", n));
}