Iterator Basic

Use iterator adaptors: map, filter, collect.

Difficulty

Intermediate

Code

fn main() {
    let nums = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

    let evens: Vec<i32> = nums.iter()
        .filter(|&&x| x % 2 == 0)
        .copied()
        .collect();
    println!("evens: {:?}", evens);

    let doubled: Vec<i32> = nums.iter().map(|&x| x * 2).collect();
    println!("doubled: {:?}", doubled);
}

Explanation

Iterators are lazy. Adaptors like map/filter are only evaluated when consumed.

Key Concepts

• Read the code carefully and understand the data flow
• Try modifying the example to see how it changes behavior
• Run this code in the Rust Playground

Related Topics

Browse more examples in the iterators category to build a complete understanding of this topic.