JSON in Rust — serde_json Guide

The de-facto standard for JSON in Rust is serde_json, built on the serde serialization framework. Add serde = { version = "1", features = ["derive"] } and serde_json = "1" to your Cargo.toml.

use serde::Deserialize;

#[derive(Deserialize, Debug)]
struct User {
    id: u32,
    name: String,
    email: String,
}

fn main() {
    let json = r#"{"id":1,"name":"Alice","email":"alice@example.com"}"#;
    let user: User = serde_json::from_str(json).unwrap();
    println!("{}", user.name); // Alice
}

use serde::Serialize;

#[derive(Serialize)]
struct User { id: u32, name: String }

let user = User { id: 1, name: "Alice".into() };

let json = serde_json::to_string(&user).unwrap();
// {"id":1,"name":"Alice"}

let pretty = serde_json::to_string_pretty(&user).unwrap();

use serde_json::Value;

let json = r#"{"name":"Alice","scores":[95,87]}"#;
let v: Value = serde_json::from_str(json).unwrap();

println!("{}", v["name"]);          // "Alice"
println!("{}", v["scores"][0]);     // 95