Rust 1.30.0

# if

There is a new edition of the book and this is an old link.

> An `if` expression allows us to branch our code depending on conditions.

    fn main() {
        let number = 3;

        if number < 5 {
            println!("condition was true");
        } else {
            println!("condition was false");
        }
    }Run

Here are the relevant sections in the new and old books:

- In the second edition: Ch 3.05 — Control flow
- In the first edition: Ch 3.5 — if