How to Collect an Iterator into Different Collection Types

Use the collect() method on an iterator to convert it into a Vec, String, HashMap, or other collection types.

let numbers = vec![1, 2, 3];
let vec: Vec<i32> = numbers.iter().collect();
let string: String = "hello".chars().collect();
let map: std::collections::HashMap<i32, i32> = [(1, 2), (3, 4)].iter().cloned().collect();

The compiler infers the target type from the variable annotation or the context where the result is used.

The collect() method gathers all items from a sequence and packs them into a specific container like a list or dictionary. It is the standard way to stop processing a stream of data and store the results for later use. Think of it as pouring water from a flowing stream into a bucket of your choice.