Nested conditions in Rust - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else blocks

What is the output of this Rust code snippet?

Rust

fn main() {
    let x = 7;
    if x > 5 {
        if x < 10 {
            println!("A");
        } else {
            println!("B");
        }
    } else {
        println!("C");
    }
}

A B

B A

C C

D No output

💡 Hint

Check the conditions step by step: is x greater than 5? Is it less than 10?

The variable x is 7, which is greater than 5 and less than 10, so the inner if prints "A".

❓ Predict Output

intermediate

Nested match with conditions output

What will this Rust program print?

Rust

fn main() {
    let num = 3;
    match num {
        1..=5 => {
            if num % 2 == 0 {
                println!("Even");
            } else {
                println!("Odd");
            }
        }
        _ => println!("Out of range"),
    }
}

A Odd

B No output

C Out of range

D Even

💡 Hint

Check if 3 is between 1 and 5, then check if it is even or odd.

3 is between 1 and 5, and 3 % 2 is 1 (odd), so it prints "Odd".

🔧 Debug

advanced

Identify the error in nested if conditions

This Rust code does not compile. What is the error?

Rust

fn main() {
    let x = 10;
    if x > 5 {
        if x < 15 {
            println!("Inside");
        }
    } else {
        println!("Outside");
    }
}

A Variable x is not mutable

B Missing braces for the outer if block

C println! macro syntax error

D The else is not matched with any if

💡 Hint

Look at how Rust matches else with the nearest if.

The else is matched with the inner if, but the outer if lacks braces, causing a syntax error.

❓ Predict Output

advanced

Output of nested if with else if

What does this Rust program print?

Rust

fn main() {
    let score = 85;
    if score >= 90 {
        println!("A");
    } else if score >= 80 {
        if score >= 85 {
            println!("B+");
        } else {
            println!("B");
        }
    } else {
        println!("C");
    }
}

A B

B C

C B+

D A

💡 Hint

Check the score against each condition carefully.

Score 85 is not >= 90, but >= 80 and also >= 85, so it prints "B+".

🧠 Conceptual

expert

How many times is the inner block executed?

Consider this Rust code snippet. How many times will the inner println! be executed?

Rust

fn main() {
    for i in 1..=5 {
        if i % 2 == 0 {
            if i > 2 {
                println!("{}", i);
            }
        }
    }
}

A 1

B 2

C 3

D 4

💡 Hint

Check which numbers from 1 to 5 are even and greater than 2.

Only 4 and 2 are even, but 2 is not greater than 2, so only 4 is printed. Also 4 is the only number printed, so 1 time.