How to handle errors in main function

Error Handling
2026-04-17T12:05:42+00:00
Return a Result type from main and use the ? operator to propagate errors gracefully instead of panicking.

Handle errors in main by returning a Result type and propagating errors with the ? operator instead of calling .unwrap() on fallible operations. This allows the program to exit gracefully with an error message when something goes wrong.

use std::thread;
use std::time::Duration;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let handle = thread::spawn(|| {
        for i in 1..10 {
            println!("hi number {i} from the spawned thread!");
            thread::sleep(Duration::from_millis(1));
        }
    });

    for i in 1..5 {
        println!("hi number {i} from the main thread!");
        thread::sleep(Duration::from_millis(1));
    }

    handle.join()?;
    Ok(())
}