Rust “Hello World!” in three languages

For our first program, we want to write something that outputs the following text in multiple languages: Hello, world! Grüß Gott! ハロー・ワールド You have probably seen the first line. The other two are there to highlight a few of Rust’s features: easy iteration and built-in support for Unicode.

fn greet_world() { 
  println!("Hello World");
  let southern_germany = "Grüß Gott!";
  let japan = "ハロー・ワールド";
  let regions = [southern_germany, japan];
  for region in regions.iter() { 
    println!("{}", &region);
  }
}

fn main() { 
  greet_world();
}

Now that src/main.rs is updated, execute cargo run from the hello2/ directory. You should see three greetings appear after some output generated from cargo itself:

$ cargo run
Finished dev [unoptimized + debuginfo] target(s) in 0.95s
Running `target/debug/hello-world`
Hello, world!
Grüß Gott!
ハロー・ワールド

Let’s take a few moments to touch on some of the interesting elements of Rust from One of the first things that you are likely to notice is that strings in Rust are able to include a wide range of characters. Strings are guaranteed to be encoded as UTF-8. This means that you can use non-English languages with relative ease. The one character that might look out of place is the exclamation mark after println. If you have programmed in Ruby, you may be used to thinking that it is used to signal a destructive operation. In Rust, it signals the use of a macro. Macros can be thought of as fancy functions for now. These offer the ability to avoid boilerplate code. In the case of println!, there is a lot of type detection going on under the hood so that arbitrary data types can be printed to the screen.