Kotlin in A..Z (24) - 연산자 오버라이딩

연산자 오버라이딩

operator 키워드를 통해 구현한다.

 

코드

class Base(var x: Int = 0) {
    operator fun plus(other: Base): Base {
        return Base(this.x + other.x)
    }

    override fun toString(): String {
        return "Base(x = $x)"
    }
}

fun main() {
    val x = Base(1)
    val y = Base(2)

    println(x + y)
}

 

결과

Base(x = 3)

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연산자 종류

표현식	의미
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..b	a.rangeTo(b)
a(b)	a.invoke(b)
a[i]	a.get(i)
a[i, j]	a.get(i, j)
a[i_1, .., i_n]	a.get(i_1, ..., i_n)
a[i] = b	a.set(i, b)
a[i, j] = b	a.set(i, j, b)
a[i_1, ..., i_n]	a.set(i_1, ..., i_n, b)
+a	a.unaryPlus()
-a	a.unaryMinus()
!a	a.not()
a in b	b.contains(a)
a !in b	!b.contains(a)
a += b	a.plusAssign(b)
a -= b	a.minusAssign(b)
a *= b	a.timesAssign(b)
a /= b	a.divAssign(b)
a %= b	a.remAssign(b)
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