mod

Calculates the remainder of flooring division of this value (dividend) by the other value (divisor).

inline fun Byte.mod(other: Byte): Byte(source)

fun main() {
    val dividend: Byte = 10
    val divisor: Byte = 3

    val remainder: Byte = dividend.mod(divisor)

    println("The remainder of $dividend รท $divisor is $remainder") // Output: 1
}

Source