while loop - Assign a value based on if condition in Scala

Question

I have a while loop that needs to create an object based on a condition happening inside the loop. The code runs fine but the object is not available once the loop finishes.

I suspect I am missing something about how variable scope works in Scala.

If what I am trying is not possible, I would like to understand why and what the alternatives are.

This is a simple example

var i = 0

while (i < 5) {
    val magicValue = if (i==2) i
    i += 1
}

println(magicValue) // error: not found: value magicValue

This is how I would do it in python

i = 0

while i<5:
    if (i==2):
        magic_value = i
    i += 1

print(magic_value) # prints 2

question from:https://stackoverflow.com/questions/65952702/assign-a-value-based-on-if-condition-in-scala

Answer 1

Please read this article read

You should use var instead of val. If you use val, this value cannot be used except in the if scope.

var i = 0
var magicValue = 0
while (i < 5){
  if(i==2) magicValue = i
   i += 1
}
println(magicValue)

demo

Each variable declaration is preceded by its type.
By contrast, Scala has two types of variables:
val creates an immutable variable (like final in Java)
var creates a mutable variable