Fizz Buzz in Rust

Welcome to the Fizz Buzz in Rust page! Here, you’ll find the source code for this program as well as a description of how the program works.

Current Solution

fn main() {
    for number in 1..101 {
        if number % 3 == 0 && number % 5 == 0 {
            println!("FizzBuzz");
        } else if number % 3 == 0 {
            println!("Fizz");
        } else if number % 5 == 0 {
            println!("Buzz");
        } else {
            println!("{}", number);
        }
    }
}

Fizz Buzz in Rust was written by:

• Noah Nichols
• Vincent Caron

If you see anything you’d like to change or update, please consider contributing.

Note: The solution shown above is the current solution in the Sample Programs repository as of Jul 12 2019 10:44:03. The solution was first committed on Sep 24 2018 13:31:57. As a result, documentation below may be outdated.

How to Implement the Solution

Let’s start by looking at the complete Fizz Buzz algorithm in Rust:

fn main() {
    for number in 1..101 {
        if number % 3 == 0 && number % 5 == 0 {
            println!("FizzBuzz");
        } else if number % 3 == 0 {
            println!("Fizz");
        } else if number % 5 == 0 {
            println!("Buzz");
        } else {
            println!("{}", number);
        }
    }
}

Before we dig into the code too much, let’s take a look at the rules:

• If a number is divisible by 3, print the word ‘Fizz’ instead of the number.
• If the number is divisible by 5, print the word ‘Buzz’ instead of the number.
• Finally, if the number is divisible by both 3 and 5, print ‘FizzBuzz’ instead of the number.
• Otherwise, just print the number.

You can test for divisibility using the modulo operator %. The modulo operator divides two numbers and yields the remainder, so i modulo j is 0 if i is divisible by j. In Rust, this is written as i % j. Then, it’s a simple matter of checking whether i % 3 == 0 or i % 5 == 0.

The Loop

In the very first line, we’ll notice a for-loop:

for number in 1..101

Here, we loop through all the numbers from 1 to 100.

Control Flow

From there, we begin our testing using an if statement:

if number % 3 == 0 && number % 5 == 0 {
    println!("FizzBuzz");
} else if number % 3 == 0 {
    println!("Fizz");
} else if number % 5 == 0 {
    println!("Buzz");
} else {
    println!("{}", number);
}

• If the number is divisible by 3 and 5, we print the word ‘FizzBuzz’.
• If the number is divisible by 3, we print the word ‘Fizz’.
• If the number is divisible by 5, we print the word ‘Buzz’.
• In all other cases, we print the number itself.

How to Run the Solution

To run FizzBuzz in Rust, install the latest version of Rust. After that, create a project structure using cargo:

cargo new fizz-buzz

Copy the code from Github into ‘main.rs’. Compile and run the code from the command line using

cargo run main.rs

This will create a new ‘target’ directory containing the executable binary file.