Description of the Hello World program¶

Previously we made a following "Hello World" program:

fn main() {
    println!("Hello World");
}

The keyword fn is for declaring [[function]]s, just like in [[C language]] - it will look for the main [[function]] to execute the program.

If we change the main to hello, an [[error]] will be thrown:

davis@davis-arch  ~/projects/rust  rustc hello.rs
error[E0601]: `main` function not found in crate `hello`
  |
  = note: consider adding a `main` function to `hello.rs`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0601`.

The println [[function]] prints a line in the [[terminal]] screen. You can also use [[placeholders]] in it.

fn main() {
    println!("Hello, {}! {}", "World", 2);
}

davis@davis-arch  ~/projects/rust  ./hello 
Hello, World! 2