Rust Program to Iterate over a HashMap

Iterate over a HashMap

Rust Programming Language

Problem

Rust program that iterates over a HashMap.

Input

use std::collections::HashMap;

fn main() {

    let mut map = HashMap::new();

    

    map.insert("apple", 3);

    map.insert("banana", 2);

    map.insert("orange", 5);

    

    println!("Map: {:?}", map);

    

    for (key, value) in &map {

        println!("{}: {}", key, value);

    }

}{codeBox}

Output

Map: {"apple": 3, "banana": 2, "orange": 5}

apple: 3

banana: 2

orange: 5{codeBox}

Explanation

In this example, we create a new HashMap and insert some key-value pairs.

We then print the contents of the map using println!("Map: {:?}", map);.

Finally, we iterate over the map using a for loop and print each key-value pair using println!("{}: {}", key, value);. The for loop iterates over references to the key-value pairs in the map, and the (key, value) pattern destructures each pair into its key and value components.

This shows the contents of the map, followed by each key-value pair printed on a separate line in the order they were added to the map. Note that the order of iteration is not guaranteed for HashMaps.