fahrenheit to celsius

background

The final section of the third chapter of the rust book ends with some suggested exercises. The first of which is to write a program to: “Convert temperatures between Fahrenheit and Celsius.”

solution

Reusing code from the guessing game chapter, we can read input, cast it to a 32 bit float through a type hint and perform the conversion:

use std::io;

fn main() {
    loop {
        println!("Degrees in Farenheit:");

        let mut degrees_f = String::new();

        io::stdin()
            .read_line(&mut degrees_f)
            .expect("Failed to read line");

        let degrees_f: f32 = match degrees_f.trim().parse() {
            Ok(num) => num,
            Err(_) => continue
        };

        let degrees_c = (degrees_f - 32.0) * 5.0/9.0;

        println!("is {degrees_c} degrees Celsius.");
    }
}