rustHow to convert JSON to a struct in Rust?

JSON can be converted to a struct in Rust using the serde crate. The serde crate provides a Deserialize trait which can be used to convert JSON data into a Rust struct.

Example code

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
struct Person {
    name: String,
    age: u8,
    phones: Vec<String>,
}

fn main() {
    // Some JSON input data as a &str. Maybe this comes from the user.
    let data = r#"
        {
            "name": "John Doe",
            "age": 43,
            "phones": [
                "+44 1234567",
                "+44 2345678"
            ]
        }"#;

    // Parse the string of data into a Person object. This is exactly the
    // same function as the one that produced serde_json::Value above, but
    // now we are asking it for a Person as output.
    let p: Person = serde_json::from_str(data).unwrap();

    // Do things just like with any other Rust data structure.
    println!("Please call {} at the number {}", p.name, p.phones[0]);
}

Output example

Please call John Doe at the number +44 1234567

Code explanation

1. use serde::{Deserialize, Serialize};: This imports the Deserialize and Serialize traits from the serde crate.

2. #[derive(Serialize, Deserialize)]: This is a Rust attribute which tells the compiler to generate code for the Serialize and Deserialize traits for the Person struct.

3. let p: Person = serde_json::from_str(data).unwrap();: This line uses the serde_json::from_str function to parse the JSON data into a Person struct.

Helpful links

• serde crate
• serde_json crate
• serde documentation

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