Exercises

Exercise 1

fn main() {
    // Booleans (`bool`)

    let is_morning = true;
    if is_morning {
        println!("Good morning!");
    }

    let // Finish the rest of this line like the example! Or make it be false!
    if is_evening {
        println!("Good evening!");
    }
}
Solution 
fn main() {
    // Booleans (`bool`)
    let is_morning = true;
    if is_morning {
        println!("Good morning!");
    }
//
    let is_evening = true; // Finish the rest of this line like the example! Or make it be false!
    if is_evening {
        println!("Good evening!");
    }
}

Exercise 2

fn main() {
    // Characters (`char`)

    // Note the _single_ quotes, these are different from the double quotes
    // you've been seeing around.
    let my_first_initial = 'C';
    if my_first_initial.is_alphabetic() {
        println!("Alphabetical!");
    } else if my_first_initial.is_numeric() {
        println!("Numerical!");
    } else {
        println!("Neither alphabetic nor numeric!");
    }

    let // Finish this line like the example! What's your favorite character?
    // Try a letter, try a number, try a special character, try a character
    // from a different language than your own, try an emoji!
    if your_character.is_alphabetic() {
        println!("Alphabetical!");
    } else if your_character.is_numeric() {
        println!("Numerical!");
    } else {
        println!("Neither alphabetic nor numeric!");
    }
}
Solution 

fn main() {
    // Characters (`char`)
    // Note the _single_ quotes, these are different from the double quotes
    // you've been seeing around.
    let my_first_initial = 'C';
    if my_first_initial.is_alphabetic() {
        println!("Alphabetical!");
    } else if my_first_initial.is_numeric() {
        println!("Numerical!");
    } else {
        println!("Neither alphabetic nor numeric!");
    }
//
    let your_character = 'A'; // Finish this line like the example! What's your favorite character?
    // Try a letter, try a number, try a special character, try a character
    // from a different language than your own, try an emoji!
    if your_character.is_alphabetic() {
        println!("Alphabetical!");
    } else if your_character.is_numeric() {
        println!("Numerical!");
    } else {
        println!("Neither alphabetic nor numeric!");
    }
}

Exercise 3

fn main() {
    let a = ???

    if a.len() >= 100 {
        println!("Wow, that's a big array!");
    } else {
        println!("Meh, I eat arrays like that for breakfast.");
        panic!("Array not big enough, more elements needed")
    }
}
Solution 
fn main() {
    let a = [0; 100];
//
    if a.len() >= 100 {
        println!("Wow, that's a big array!");
    } else {
        println!("Meh, I eat arrays like that for breakfast.");
    }
}

Exercise 4

#![allow(unused)]
fn main() {
#[test]
fn slice_out_of_array() {
    let a = [1, 2, 3, 4, 5];

    let nice_slice = ???

    assert_eq!([2, 3, 4], nice_slice)
}
}
Solution 
#![allow(unused)]
fn main() {
#[test]
fn slice_out_of_array() {
    let a = [1, 2, 3, 4, 5];
//
    let nice_slice = &a[1..4];
//
    assert_eq!([2, 3, 4], nice_slice)
}
}

Exercise 5

fn main() {
    let cat = ("Furry McFurson", 3.5);
    let /* your pattern here */ = cat;

    println!("{} is {} years old.", name, age);
}
Solution 
fn main() {
    let cat = ("Furry McFurson", 3.5);
    let (name, age)/* your pattern here */ = cat;
//
    println!("{} is {} years old.", name, age);
}

Exercise 6

#![allow(unused)]
fn main() {
#[test]
fn indexing_tuple() {
    let numbers = (1, 2, 3);
    // Replace below ??? with the tuple indexing syntax.
    let second = ???;

    assert_eq!(2, second,
        "This is not the 2nd number in the tuple!")
}
}
Solution 
#![allow(unused)]
fn main() {
#[test]
fn indexing_tuple() {
    let numbers = (1, 2, 3);
    // Replace below ??? with the tuple indexing syntax.
    let second = numbers.1;
//
    assert_eq!(2, second,
        "This is not the 2nd number in the tuple!")
}
}