Rust MCQ Questions with answers and solutions Page 3

Q. What is the purpose of lifetimes in Rust?

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✅ Correct Answer: (C) To ensure memory safety

Explanation: Lifetimes help Rust ensure references are valid and prevent dangling pointers.

Published by Admin ⭐ 38.23K Points at 26-Sep-2025 08:00 pm in Rust

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✅ Correct Answer: (B) Option

Explanation: 'Option' is used to represent a value that may or may not be present.

Published by Admin ⭐ 38.23K Points at 26-Sep-2025 08:00 pm in Rust

Code:

fn main() {
    let x = 10;
    let y = &x;
    println!("{}", y);
}

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✅ Correct Answer: (A) 10

Explanation: Rust automatically dereferences references in println!, so it prints 10.

Published by Admin ⭐ 38.23K Points at 26-Sep-2025 08:00 pm in Rust

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✅ Correct Answer: (C) Ownership and borrowing

Explanation: Rust uses ownership and borrowing to manage memory safely without a garbage collector.

Published by Admin ⭐ 38.23K Points at 26-Sep-2025 08:00 pm in Rust

Code:

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

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✅ Correct Answer: (B) 6

Explanation: The variable 'x' is mutable and incremented by 1, resulting in 6.

Published by Admin ⭐ 38.23K Points at 26-Sep-2025 08:00 pm in Rust