Operators and Boolean conditions

A certificate can require both a sufficient mark and sufficient attendance. Comparisons produce bool values, and logical operators combine them. Separating arithmetic from comparisons helps you see whether a mistake concerns a calculation or the policy applied to it.

>= includes the boundary; && requires both conditions and || requires at least one. These logical operators short-circuit: they do not evaluate the second operand when the first determines the answer. The remainder operator % answers how much is left after integer division.

Save the complete source as main.rs in the Rust environment. No standard input is needed.

Rust 2024 · complete program

fn main() {
  let score = 75;
  let attendance = 9;
  println!("{}", score >= 75 && attendance >= 8);
  println!("{} {}", 17 / 5, 17 % 5);
}

Expected output

true
3 2

Follow the execution

Both comparisons are true. Seventeen divided by five has quotient three and remainder two: 17 equals 3 × 5 + 2. Equality uses ==; writing = instead changes a binding where assignment is allowed.

Try the complete program in the Rust compiler. For tests, Cargo commands and local files, use the specified local environment.

Your task: If attendance becomes seven, is the student eligible?

Rust 2024 · complete program

fn main() {
  let score = 75;
  let attendance = 9;
  println!("{}", score >= 75 && attendance >= 8);
  println!("{} {}", 17 / 5, 17 % 5);
}

Worked answer

No. The rule requires both comparisons to be true. A sufficient mark does not replace the separate attendance requirement.

Parentheses make a complex policy easier to review. Rust does not treat an arbitrary integer as a Boolean condition. A technically valid expression can still encode the wrong policy, so test its boundaries.

No. The rule requires both comparisons to be true. A sufficient mark does not replace the separate attendance requirement. Parentheses make a complex policy easier to review.

Further reading: the official Rust Book on operators and boolean conditions.