rustHow to sort the keys in a Rust HashMap?

Rust HashMap can be sorted by its keys using the .iter() method. This method returns an iterator over the key-value pairs in the map, sorted by the keys.

Example code

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

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

Output example

a: 1
b: 2
c: 3

Code explanation

• use std::collections::HashMap;: imports the HashMap type from the standard library.
• let mut map = HashMap::new();: creates a new empty HashMap.
• map.insert("a", 1);: inserts a key-value pair into the HashMap.
• for (key, value) in map.iter() {: iterates over the key-value pairs in the map, sorted by the keys.
• println!("{}: {}", key, value);: prints the key-value pair.

Helpful links

• Rust HashMap Documentation

Edit this code on GitHub