The following piece of code raises type error

[Souvik]

Hi,
I am a beginner and wrote a code to convert temperature from celsius to fahrenheit.
Code:-

    use std::io;
fn main() {
    //converting temperature from fahrenheit to celsius.
    let mut temp = String::new();
    let mut choice = String::new();
    println!("This program converts temperature from celcius to fahrenheit");
    println!("To convert temperature from celcius to fahreheit press 1.");
    println!("To convert temperature from fahrenheit to celcius press 2.");
    println!("Enter your choice: ");
    loop {
        io::stdin()
            .read_line(&mut choice)
            .expect("Unable to read line!");
        println!("Enter temperature");
        let choice: u32 = match choice.trim().parse() {
            Ok(num) => num,
            Err(_) => {
                println! {"Invalid input!"};
                continue;
            }
        };
    }
    loop {
        io::stdin()
            .read_line(&mut temp)
            .expect("Unable to read line!");
        let temp: u32 = match temp.trim().parse() {
            Ok(num) => num,
            Err(_) => {
                println!("Invalid input!");
                continue;
            }
        };
    }
// The equalto (==) operator causes the problem.
    if choice == 1 {
        println!("{}", cel_to_fah(temp));
    } else if choice == 2 {
        println!("{}", fah_to_cel(temp));
    } else {
        println!("Invalid choice, aborting!")
    }
}

fn cel_to_fah(temp: u32) -> u32 {
    (temp * 9 / 5) + 32
}

fn fah_to_cel(temp: u32) -> u32 {
    (temp - 32) * 5 / 9
}

And it raised the error:- mismatched types
expected u32, found struct std::string::Stringrustc(E0308)
main.rs(36, 35): expected u32, found struct std::string::String
I don't know why the error is raised and how to correct the code. Please help. Thank you.

[drewkett]

You’ve changed the type of the variable when you are doing parse since you’re reusing the same variable name. In the loop, the second time through you’re passing a u32 to read_line. Try using a different variable name for the u32 version of the temperature variable.

Also in general please format code by putting it in code blocks. It makes it much easier to read

```
Code goes here
```

[FedericoStra]

Several issues:

• The Err tuple variant has 1 field, so you need an Err(_) pattern.
• The variables choice: u32 and temp: u32 are local to the two loops, they are not visible in main after the loops.
• In choice == 1 you are comparing the variable choice: String with an integer, which is not valid.
• u32 is not a suitable type to represent temperature. What about negative values?

Here is a simple refactor. Notice that it doesn't address the last issue, which is left as an exercise. Try running it an entering choice = 2, temp = 31.

Edit: also, Celsius is spelt Celsius, not Celcius.

[Souvik]

Aah, thanks for all the help. And celcius has just become a habit, sorry . And also extremely sorry for not formatting the code.

Souvik flutter dev