What are error handling best practices

Use Result<T, E> for recoverable errors and panic! only for unrecoverable ones.

use std::fs::File;
use std::io::ErrorKind;

fn read_file(path: &str) -> Result<String, std::io::Error> {
    let mut file = File::open(path)?;
    let mut contents = String::new();
    file.read_to_string(&mut contents)?;
    Ok(contents)
}

fn main() {
    match read_file("hello.txt") {
        Ok(content) => println!("{content}"),
        Err(e) if e.kind() == ErrorKind::NotFound => println!("File not found"),
        Err(e) => panic!("Unexpected error: {e}"),
    }
}

The ? operator propagates errors automatically, while match lets you handle specific cases like NotFound before panicking on unexpected failures.

Think of error handling like a safety net: catch expected slips (like a missing file) so the program keeps running, but stop immediately if something truly breaks. You use Result to gracefully handle things that might go wrong, and panic! only when the program cannot possibly continue safely.