Serialize and deserialize HashMap to JSON in Rust

---

examples/json/serialize-hashmap/Cargo.toml

[package]
name = "serialize-hashmap"
version = "0.1.0"
edition = "2021"

[dependencies]
serde_json = "1.0.120"

examples/json/serialize-hashmap/src/main.rs

use std::collections::HashMap;

fn main() {
    let mut data_before = HashMap::new();
    data_before.insert(String::from("foo"), 23);
    data_before.insert(String::from("bar"), 42);
    println!("{:?}", data_before);

    // serialize
    let json_string = serde_json::to_string(&data_before).unwrap();
    println!("{}", json_string);

    // deserialize
    let data_after: HashMap<String, u32> = serde_json::from_str(&json_string).unwrap();
    println!("{:?}", data_after);
    assert_eq!(data_before, data_after);

    // doing the same using Turbofish
    let data_turbofish = serde_json::from_str::<HashMap<String, u32>>(&json_string).unwrap();
    println!("{:?}", data_turbofish);
    assert_eq!(data_before, data_turbofish);
}

{"foo": 23, "bar": 42}
{"foo":23,"bar":42}
{"bar": 42, "foo": 23}
{"foo": 23, "bar": 42}