1. 迭代适配器
```
let v1 = vec![1, 3, 4, 6];
let v2:Vec<_> = v1.iter().map(|x| x + 1).collect();
println!("{:?}", v2);//输出：[2, 4, 5, 7]
let v1 = vec![1, 5, 12, 9, 10];
let v2:Vec<_> = v1.into_iter().filter(|x| *x >= 10).collect();
println!("{:?}", v2);//过滤：[12, 10]
```
2. 消费迭代器
```
let v1 = vec![1, 4, 5];
let total: i32 = v1.iter().sum();//求和
println!("{}", total);//输出10
```
3. 迭代可变引用
```
let mut v1 = vec![1, 3, 5, 7];
if let Some(v) = v1.iter_mut().next() {
*v = 3;
}
println!("{:?}", v1);//输出 [3, 3, 5, 7]
```
4. 迭代的遍历
```
let v1 = vec![1, 4, 5, 6];
for v in v1.iter() {
println!("{}", v);
}
```
