I'm new to Kotlin and I don't know where I went wrong with this.
fun swap(a:Int,b:Int):Unit{ a=a xor b b=b xor a a=a xor b } fun main() { var a =10 var b = 1000 // swap(a, b) //print("$a, %b") } I get these errors.enter image description here Thanks!
I was trying to use
ref key word but it doesn't work
I am no expert to Kotlin, but I'd say you can't achieve this in the way you wrote it.
Check out this answer to question Is Kotlin "pass-by-value" or "pass-by-reference"?. In short, the parameters your function retrieves are passed-by-value and, as such, cannot be swapped. They're not your C pointers.
Now, another answer on StackOverflow explains why you don't even need a swap function in Kotlin and how you can implement the swapping behavior:
var a = 1 var b = 2 a = b.also { b = a } println(a) // print 2 println(b) // print 1 Now if you really want to implement a swap function, since the JVM world is pass-by-value, you could implement a wrapper to wrap your integers, something like:
// NOTE You have to use "var" not "val". data class IntWrapper(var value: Int) fun swap(a: IntWrapper, b: IntWrapper) { a.value = a.value xor b.value b.value = b.value xor a.value a.value = a.value xor b.value } Check out working example.
KMutableProperty0<Int>and replace the assignments and accesses withsetandget. Either way, there are much better ways to write aswap.