表达式 | 翻译为 |
---|---|
+a | a.unaryPlus() |
-a | a.unaryMinus() |
!a | a.not() |
a + b | a.plus(b) |
a - b | a.minus(b) |
a * b | a.times(b) |
a / b | a.div(b) |
a % b | a.rem(b)、 a.mod(b) (已弃用) |
a..b | a.rangeTo(b) |
a in b | b.contains(a) |
a !in b | !b.contains(a) |
a == b | a?.equals(b) ?: (b === null) |
a != b | !(a?.equals(b) ?: (b === null)) |
a > b | a.compareTo(b) > 0 |
a < b | a.compareTo(b) < 0 |
a >= b | a.compareTo(b) >= 0 |
a <= b | a.compareTo(b) <= 0 |
a() | a.invoke() |
a(i) | a.invoke(i) |
a(i, j) | a.invoke(i, j) |
a(i_1, ……, i_n) | a.invoke(i_1, ……, i_n) |
unaryMinus
data class Point(val x: Int, val y: Int)
operator fun Point.unaryMinus() = Point(-x, -y)
val point = Point(10, 20)
fun main() {
println(-point) // 输出“Point(x=-10, y=-20)”
}
plus
data class Counter(val dayIndex: Int) {
operator fun plus(increment: Int): Counter {
return Counter(dayIndex + increment)
}
}
invoke
class Hello{
operator fun invoke(target: String) {
say()
println(target)
}
fun say() {
println("hello ")
}
}
fun main() {
val hello = Hello()
hello("world")
}