In Kotlin how Immutable parameters affect space complexity if you have to copy the input every time-CodePudding

In Kotlin, function parameters are immutable, so you cannot modify the parameter in the code without making a copy first, does this affect space complexity, and does it prevent in-place modification, thus preventing it from having O(1) constant? What is the solution to this?

fun replaceFirstElement(nums: IntArray, number: Int) {
    // not working
    nums[0] = number
}

CodePudding user response：

An array in Kotlin is always mutable, also when handed over as argument to a function. It is fixed-sized, but the elements are mutable:

fun replaceFirstElement(nums: IntArray, number: Int) {
  nums[0] = number
}

val intArray = IntArray(10) { it   1 }

replaceFirstElement(intArray, 99)

intArray.forEach { println(it) }

Output:

This also applies to the other array types, and to the mutable collection like MutableList, MutableMap, etc.