The Ultimate Guide to Rust Programming/

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Exercises

Exercises

We'll cover the following...

Exercise 1

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fn main() {
    if 5 == 5 {
        println!("5 == 5 is true");
    }
    if 5 > 5 {
        println!("5 > 5 is true");
    }
    if 5 >= 5 {
        println!("5 >= 5 is true");
    }
}
Q

What is the output of this program?

A)

5 == 5 is true

5 >= 5 is true

B)

5 == 5 is true

5 > 5 is true

C)

5 >= 5 is true

5 > 5 is true

Exercise 2

Replace all four FIXMEs below with the correct type:

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fn want_apples() -> bool {
    true
}
fn want_five() -> bool {
    false
}
fn talk_about_fruit() -> bool {
    true
}
fn talk_about_numbers() -> bool {
    false
}
fn main() {
    let fruit: FIXME = if want_apples() {
        "apple"
    } else {
        "banana"
    };
    let number: FIXME = if want_five() {
        5
    } else {
        6
    };
    let _x: FIXME = if talk_about_fruit() {
        println!("The fruit is {}", fruit);
    };
    let _y: FIXME = if talk_about_numbers() {
        println!("The number is {}", number);
    };
}

Exercise 3

Rewrite the program below so it doesn’t use any lets. Reminder: you can put any expression inside a macro call’s parameter list.

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fn comment(apples: i32) {
    let message = if apples > 10 {
        "lots of"
    } else {
        "very few"
    };
    println!("You have {} apples", message);
}
fn main() {
    comment(5);
    comment(100);
}

Exercise 4

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