What is Rust - Practice Questions & Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the main focus of Rust?

Rust is a programming language designed with a special focus. What is its main focus?

A Primarily for web page styling

B Dynamic typing and rapid prototyping

C Automatic memory management with garbage collection

D Memory safety without using a garbage collector

💡 Hint

Think about how Rust handles memory compared to languages like Java or Python.

Rust focuses on memory safety without a garbage collector by using ownership and borrowing rules.

❓ Predict Output

intermediate

What is the output of this Rust code?

Look at this Rust code snippet. What will it print?

Rust

fn main() {
    let x = 5;
    let y = &x;
    println!("{}", y);
}

A 5

B Compilation error

C Memory address of x

D x

💡 Hint

Remember that &x is a reference to x, and println! with {} prints the value.

The code prints the value 5 because y is a reference to x, and println! dereferences it automatically.

❓ Predict Output

advanced

What error does this Rust code produce?

What error will this Rust code cause when compiled?

Rust

fn main() {
    let mut s = String::from("hello");
    let r1 = &s;
    let r2 = &s;
    let r3 = &mut s;
    println!("{} {} {}", r1, r2, r3);
}

A Syntax error: missing semicolon

B Cannot borrow `s` as mutable because it is also borrowed as immutable

C No error, prints: hello hello hello

D Use of moved value `s`

💡 Hint

Rust does not allow mutable and immutable references at the same time.

The code tries to borrow `s` as mutable while immutable references exist, which Rust forbids.

🚀 Application

advanced

How does Rust ensure thread safety?

Rust uses a special system to ensure safe access to data across threads. What is this system called?

A Garbage collection with locks

B Manual memory management with pointers

C Ownership and borrowing rules enforced at compile time

D Dynamic typing with runtime checks

💡 Hint

Think about how Rust prevents data races without runtime overhead.

Rust uses ownership and borrowing rules checked at compile time to prevent data races and ensure thread safety.

🧠 Conceptual

expert

What is the role of the Rust compiler's borrow checker?

What does the borrow checker in Rust do?

A It enforces rules about references to prevent invalid memory access at compile time

B It manages garbage collection automatically during runtime

C It optimizes code for faster execution by reordering instructions

D It converts Rust code into machine code without checks

💡 Hint

Consider how Rust prevents bugs related to references before the program runs.

The borrow checker enforces ownership and borrowing rules at compile time to prevent invalid memory access.