0x13b Iterators

Review

  1. 2024-07-07 07:47

一、Introduction #

In Rust, iterators are lazy, meaning they have no effect until you call methods that consume the iterator to use it up.

    let v1 = vec![1, 2, 3];

    let v1_iter = v1.iter();

    for val in v1_iter {
        println!("Got: {val}");
    }
    #[test]
    fn iterator_demonstration() {
        let v1 = vec![1, 2, 3];

        let mut v1_iter = v1.iter();

        assert_eq!(v1_iter.next(), Some(&1));
        assert_eq!(v1_iter.next(), Some(&2));
        assert_eq!(v1_iter.next(), Some(&3));
        assert_eq!(v1_iter.next(), None);
    }

iter
into_iter takes ownership of the vector iter_mut

    #[test]
    fn iterator_sum() {
        let v1 = vec![1, 2, 3];

        let v1_iter = v1.iter();

        let total: i32 = v1_iter.sum();

        assert_eq!(total, 6);
    }

Methods #

  1. map
  2. collect
  3. filter

Reference #