rustHow to drain a Rust HashMap?

A Rust HashMap can be drained using the drain method. This method returns an iterator over the key-value pairs in the map, which can then be used to remove the elements from the map.

Example code

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);

for (key, value) in map.drain() {
    println!("key: {} value: {}", key, value);
}

Output example

key: a value: 1
key: b value: 2

Code explanation

1. let mut map = HashMap::new(); - This line creates a new empty HashMap.
2. map.insert("a", 1); - This line inserts a key-value pair into the HashMap.
3. for (key, value) in map.drain() { - This line creates an iterator over the key-value pairs in the map.
4. println!("key: {} value: {}", key, value); - This line prints out the key-value pairs.
5. } - This line ends the loop.

Helpful links

• Rust HashMap Documentation

Edit this code on GitHub