Rustlings Topic: Quiz

in Study Log on Rust, Rustlings

Finally the last topic of the Rustlings!
I honestly didn’t think writing solutions would take this long. But finally, I’ve made it!

Kudos to me!

You may find solution code for the topic from my repo.

  1. quiz1.rs
  2. quiz2.rs
  3. quiz3.rs
  4. quiz4.rs

quiz1.rs

/* file: "exercises/quiz1.rs" */
fn calculate_apple_price(total_apple: i32) -> i32 {
    if total_apple > 40 {
        total_apple
    } else {
        total_apple * 2
    }
}

// Don't modify this function!
#[test]
fn verify_test() {
    let price1 = calculate_apple_price(35);
    let price2 = calculate_apple_price(40);
    let price3 = calculate_apple_price(65);

    assert_eq!(70, price1);
    assert_eq!(80, price2);
    assert_eq!(65, price3);
}

quiz2.rs

/* file: "exercises/quiz2.rs" */
fn string_slice(arg: &str) {
    println!("{}", arg);
}
fn string(arg: String) {
    println!("{}", arg);
}

fn main() {
    string_slice("blue");
    string("red".to_string());
    string(String::from("hi"));
    string("rust is fun!".to_owned());
    string("nice weather".into());
    string(format!("Interpolation {}", "Station"));
    string_slice(&String::from("abc")[0..1]);
    string_slice("  hello there ".trim());
    string("Happy Monday!".to_string().replace("Mon", "Tues"));
    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
}

quiz3.rs

/* file: "exercises/quiz3.rs" */
pub fn times_two(num: i32) -> i32 {
    num * 2
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn returns_twice_of_positive_numbers() {
        assert_eq!(times_two(4), 8);
    }

    #[test]
    fn returns_twice_of_negative_numbers() {
        assert_eq!(times_two(-4), -8)
    }
}

quiz4.rs

/* file: "exercises/quiz4.rs" */
macro_rules! my_macro {
    ($val:expr) => {
        format!("Hello {}", $val);
    };
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_my_macro_world() {
        assert_eq!(my_macro!("world!"), "Hello world!");
    }

    #[test]
    fn test_my_macro_goodbye() {
        assert_eq!(my_macro!("goodbye!"), "Hello goodbye!");
    }
}

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