Relational operators in Rust - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of chained relational operators

What is the output of this Rust code snippet?

Rust

fn main() {
    let a = 5;
    let b = 10;
    let c = 15;
    println!("{}", a < b && b < c);
}

A Compilation error

B false

C true

D Runtime panic

💡 Hint

Think about how logical AND works with relational operators.

The expression a < b && b < c checks if a is less than b AND b is less than c. Both are true, so the output is true.

❓ Predict Output

intermediate

Result of comparing floating-point numbers

What will this Rust program print?

Rust

fn main() {
    let x = 0.1 + 0.2;
    let y = 0.3;
    println!("{}", x == y);
}

A Compilation error

B false

C true

D Runtime panic

💡 Hint

Floating-point arithmetic can be tricky due to precision.

Due to floating-point precision, 0.1 + 0.2 is not exactly equal to 0.3, so the comparison returns false.

❓ Predict Output

advanced

Output of relational operators with characters

What does this Rust code print?

Rust

fn main() {
    let ch1 = 'a';
    let ch2 = 'A';
    println!("{}", ch1 > ch2);
}

A Runtime panic

B false

C Compilation error

D true

💡 Hint

Characters are compared by their Unicode values.

The Unicode value of 'a' is greater than 'A', so the expression ch1 > ch2 is true.

❓ Predict Output

advanced

Relational operator with references

What is the output of this Rust program?

Rust

fn main() {
    let x = 10;
    let y = 20;
    let px = &x;
    let py = &y;
    println!("{}", px < py);
}

A Compilation error

B false

C true

D Runtime panic

💡 Hint

Check if Rust allows direct comparison of references with < operator.

Rust does not implement the < operator for references to integers directly, so this code causes a compilation error.

🧠 Conceptual

expert

Understanding relational operator precedence

Consider this Rust expression: 3 + 4 > 5 && 2 * 2 == 4. What is the value of this expression?

A true

B false

C Compilation error

D Runtime panic

💡 Hint

Remember operator precedence: arithmetic before relational, then logical.

3 + 4 is 7, which is greater than 5 (true). 2 * 2 is 4, equal to 4 (true). true && true is true.