How to do it...

1. In the src/bin folder, create a file called format.rs
2. Add the following code and run it with cargo run --bin format

1  fn main() {
2    let colour = "red";
3    // The '{}' it the formatted string gets replaced by the
   parameter
4    let favourite = format!("My favourite colour is {}", colour);
5    println!("{}", favourite);
6     
7    // You can add multiple parameters, which will be
8    // put in place one after another
9    let hello = "hello ";
10   let world = "world!";
11   let hello_world = format!("{}{}", hello, world);
12   println!("{}", hello_world); // Prints "hello world!"
13     
14   // format! can concatenate any data types that
15   // implement the 'Display' trait, such as numbers
16   let favourite_num = format!("My favourite number is {}", 42);
17   println!("{}", favourite_num); // Prints "My favourite number
     is 42"
18     
19   // If you want to include certain parameters multiple times
20   // into the string, you can use positional parameters
21   let duck_duck_goose = format!("{0}, {0}, {0}, {1}!", "duck",
     "goose");
22   println!("{}", duck_duck_goose); // Prints "duck, duck, duck,
     goose!"
23     
24   // You can even name your parameters!
25   let introduction = format!(
26     "My name is {surname}, {forename} {surname}",
27     surname="Bond",
28     forename="James"
29   );
30   println!("{}", introduction) // Prints "My name is Bond, James
     Bond"
31  }