- Open the Cargo.toml file that was generated earlier for you
- Under [dependencies], add the following line:
rand = "0.3"
- If you want, you can go to rand's crates.io page (https://crates.io/crates/rand) to check for the newest version and use that one instead
-
In the bin folder, create a file called rand.rs
-
Add the following code and run it with cargo run --bin rand:
1 extern crate rand;
2
3 fn main() {
4 // random_num1 will be any integer between
5 // std::i32::MIN and std::i32::MAX
6 let random_num1 = rand::random::<i32>();
7 println!("random_num1: {}", random_num1);
8 let random_num2: i32 = rand::random();
9 println!("random_num2: {}", random_num2);
10 // The initialization of random_num1 and random_num2
11 // is equivalent.
12
13 // Every primitive data type can be randomized
14 let random_char = rand::random::<char>();
15 // Altough random_char will probably not be
16 // representable on most operating systems
17 println!("random_char: {}", random_char);
18
19
20 use rand::Rng;
21 // We can use a reusable generator
22 let mut rng = rand::thread_rng();
23 // This is equivalent to rand::random()
24 if rng.gen() {
25 println!("This message has a 50-50 chance of being
printed");
26 }
27 // A generator enables us to use ranges
28 // random_num3 will be between 0 and 9
29 let random_num3 = rng.gen_range(0, 10);
30 println!("random_num3: {}", random_num3);
31
32 // random_float will be between 0.0 and 0.999999999999...
33 let random_float = rng.gen_range(0.0, 1.0);
34 println!("random_float: {}", random_float);
35
36 // Per default, the generator uses a uniform distribution,
37 // which should be good enough for nearly all of your
38 // use cases. If you require a particular distribution,
39 // you specify it when creating the generator:
40 let mut chacha_rng = rand::ChaChaRng::new_unseeded();
41 let random_chacha_num = chacha_rng.gen::<i32>();
42 println!("random_chacha_num: {}", random_chacha_num);
43 }