Operators and Boolean conditions

A school rule can require both a sufficient score and attendance. Comparisons produce Boolean values, and logical operators combine them. Arithmetic operators calculate quantities, so it helps to trace those stages separately rather than treating every symbol as a decision.

>= includes its boundary. && requires both conditions; || requires at least one. These logical operators short-circuit when the first operand determines the result. Kotlin uses == for structural equality and === for reference identity; the latter is not a general replacement for value comparison.

Save the complete source as Main.kt and use the Kotlin/JVM environment. No separate input file is needed.

Kotlin/JVM · complete program

fun main() {
  val score = 75
  val attended = 9
  println(score >= 75 && attended >= 8)
  println(17 / 5)
  println(17 % 5)
}

Expected output

true
3
2

Follow the execution

Both eligibility comparisons are true. Seventeen divided by five has integer quotient three and remainder two, because 17 equals 3 × 5 + 2. Assignment, equality and identity each ask a different question.

Try this in the Kotlin compiler by pasting the complete program.

Your task: What happens to eligibility if attendance becomes seven?

Kotlin/JVM · complete program

fun main() {
  val score = 75
  val attended = 9
  println(score >= 75 && attended >= 8)
  println(17 / 5)
  println(17 % 5)
}

Worked answer

It becomes false because the rule requires both conditions. A sufficient score does not compensate for a failed attendance requirement in this written policy.

Use parentheses when grouping is unclear. Integer division by zero fails rather than returning a useful mark. Do not use reference identity to compare the numerical or textual meaning of ordinary values.

It becomes false because the rule requires both conditions. A sufficient score does not compensate for a failed attendance requirement in this written policy. Use parentheses when grouping is unclear.

Further reading: official Kotlin documentation for this topic.