Printing a variable

One thing that annoys me about println! macro is that we cannot just put a variable in it and get it printed. We need to include a formatting string with placeholders for the values or with interpolation as we saw it earlier.

The following code will NOT compile. At least the compiler will give you a semi-understandable hint how to fix it.

fn main() {
    let name = "Foo";
    println!(name);
}

The error message:

error: format argument must be a string literal
 --> examples/intro/formatting_required.rs:3:14
  |
3 |     println!(name);
  |              ^^^^
  |
help: you might be missing a string literal to format with
  |
3 |     println!("{}", name);
  |              +++++

error: aborting due to previous error

Coming from languages such as Perl and Python I used do way too much debugging by sprinkling print-statements around the code. Even in those languages after a while, as the program grows I always switch to logging, but still.

Given that Rust is a compiled language where the compilation takes a lot longer than in Perl or Python, this strategy is less useful, but still, I'd like my simple printing for debugging back. Luckily Rust provides it.