how do I increment an integer variable I passed into a function in Scala?
immutability, parameter-passing, scala
Solution
First of all, I will repeat my words of caution: solution below is both obscure and inefficient, if it possible try to stick with `val`ues.
implicit class MutableInt(var value: Int) {
def inc() = { value+=1 }
}
def function(s: MutableInt): Boolean={
s.inc() // parentheses here to denote that method has side effects
return true
}
And here is code in action:
scala> val x: MutableInt = 0
x: MutableInt = MutableInt@44e70ff
scala> function(x)
res0: Boolean = true
scala> x.value
res1: Int = 1
Problem
I declared a variable outside the function like this: ``` var s: Int = 0 ``` passed it such as this: ``` def function(s: Int): Boolean={ s += 1 return true } ``` but the error lines wont go away under the "s +=" for the life of me. I tried everything. I am new to Scala btw.