Why Rust is used - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print a message about Rust's safety.

Rust

fn main() {
    println!("Rust is {} and fast.");
}

Drag options to blanks, or click blank then click option'

Aslow

Bsafe

Ccomplicated

Dunstable

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'slow' because of unfamiliarity with Rust's speed.

Rust is known for being safe and fast, which helps prevent bugs.

2fill in blank

medium

Complete the code to declare a variable that cannot be changed in Rust.

Rust

fn main() {
    let [1] = 10;
    // This variable cannot be changed
}

Drag options to blanks, or click blank then click option'

Ax

Bvar x

Cmut x

Dconst x

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'mut x' which makes the variable mutable.

In Rust, variables are immutable by default. Just 'let x' means it cannot be changed.

3fill in blank

hard

Fix the error in the Rust code that tries to change an immutable variable.

Rust

fn main() {
    let mut x = 5;
    x = [1];
    println!("x is {}", x);
}

Drag options to blanks, or click blank then click option'

A10

Bx + 1

Cmut x

Dlet x

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to assign 'mut x' or 'let x' inside the function body.

The error is trying to assign a new value to an immutable variable. To fix, declare 'x' as mutable or avoid reassignment. Here, just assigning a value to 'x' is the fix.

4fill in blank

hard

Fill both blanks to create a Rust function that returns the sum of two numbers.

Rust

fn sum(a: i32, b: i32) -> i32 {
    [1] a + b;
}

fn main() {
    let result = sum(5, 7);
    println!("Sum is: {}", [2]);
}

Drag options to blanks, or click blank then click option'

Aa + b

Breturn

Cresult

Da - b

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'a + b' as a statement without 'return' or missing the variable in print.

The function uses 'return' to send back the sum. Then 'result' holds the sum to print.

5fill in blank

hard

Fill all three blanks to create a Rust program that uses a vector and prints its length.

Rust

fn main() {
    let mut numbers = Vec::new();
    numbers.[1](10);
    numbers.[2](20);
    println!("Length is: {}", numbers.[3]());
}

Drag options to blanks, or click blank then click option'

Apush

Bpop

Clen

Dinsert

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'pop' which removes elements instead of adding.

'push' adds elements to the vector. 'len' returns the number of elements.