How to write to a file

Use std::fs::write to create a file or overwrite its contents with a string in one call.

use std::fs;

fn main() -> std::io::Result<()> {
    fs::write("hello.txt", "Hello, world!")?;
    Ok(())
}

For more control, like appending or writing in chunks, use File and BufWriter from std::fs and std::io.

Writing to a file in Rust saves text to your computer like putting a note in a folder; the code creates the file if it doesn't exist or replaces the old note if it does. You use this whenever your program needs to save data permanently.