How do I print variables in Rust and have it show everything about that variable, like Ruby's .inspect?

Question

use std::collections::HashMap;

fn main() {
    let mut hash = HashMap::new();
    hash.insert(\"Daniel\", \"798-1364\");
    println!(\"{}\", hash);
}

Answer 1

Rust 1.32 introduced the dbg macro:

use std::collections::HashMap;

fn main() {
    let mut hash = HashMap::new();
    hash.insert("Daniel", "798-1364");
    dbg!(hash);
}

This will print:

[src/main.rs:6] hash = {
    "Daniel": "798-1364"
}

Answer 2

What you're looking for is the Debug formatter:

use std::collections::HashMap;

fn main() {
    let mut hash = HashMap::new();
    hash.insert("Daniel", "798-1364");
    println!("{:?}", hash);
}

This should print:

{"Daniel": "798-1364"}

See also:

• What is the difference between println's format styles?